Old build, or original build?
They sound similar and they are not the same request.
An older build is a previous release of the app. People go looking for one when an update broke something on their handset, or when a newer version stopped supporting a phone that used to run it fine. That is a version problem.
An original build is the genuine file as the operator published it, as opposed to a repackaged copy that somebody else has opened up, modified and put back online under the same name. That is an authenticity problem, and it has nothing to do with how old the file is.
The confusion matters because the second one is the dangerous one. An old official build is merely out of date. A repackaged build of any age is a different piece of software wearing the same icon, and you are about to put money through it.
Whichever brought you here, run the same check first: the current release is version 23.1 at 36.9 MB, it asks for eight permissions, and none of them reach your storage, contacts, location, camera, microphone or messages. A file that does not match that description is not the official current build, whatever the page you got it from called it.
Why people go looking for an older build
An update broke something
The most legitimate reason. A new build runs badly on a specific handset, or a room you play stopped loading. Worth reporting to support before rolling back, because a device specific bug they do not know about does not get fixed.
The phone is too old
Newer builds raise the minimum Android version over time. If your handset sits below the current minimum, an older build genuinely is the only route, and it is the one case where the trade is clearly worth it.
Something looked better before
Interface changes are the common complaint. Understandable, and the weakest reason to stay behind, because it trades security fixes for familiarity.
What staying on an old build costs you
Security fixes stop arriving. This is the real cost and it is easy to ignore because nothing visibly changes. An app handling deposits and withdrawals is not a good place to run known unpatched code.
Server side changes will eventually break it. The app talks to servers that keep moving. At some point an old client stops being able to hold a conversation with them, and the failure is usually not graceful. Rooms stop loading or payments stop completing.
New rooms do not appear. Games added to the catalogue after your build shipped will not be in your lobby, and the ones you have may not receive fixes.
Support has less to work with. The first thing any support desk asks is which version you are on. An answer that is several releases behind narrows what they can do for you, and reasonably so.
None of that makes rolling back wrong. It makes it a decision with a cost, worth taking deliberately and worth reversing once whatever drove it is fixed.
If you roll back anyway
Expect the app to undo it. It updates itself and it will tell you a newer version is available, so a rollback does not stay put on its own. If you went back for a specific reason, you will be asked about the newer build again.
Expect to uninstall first. Android will not install an older version over a newer one. Uninstalling does not touch your account, which lives on the server against your mobile number, so nothing is lost and nothing needs backing up.
Run the authenticity checks properly. An old build from a mirror is exactly the situation the permission list exists for. Eight permissions, none of them reaching storage, contacts, location, camera, microphone, SMS or phone state.
Go back to current as soon as you can. If you rolled back because of a bug, check after the next release rather than settling in.
Version questions
How do I know I have the original Jaiho Arcade APK?
Match it against the current release: version 23.1, 36.9 MB, eight permissions and none of them touching storage, contacts, location, camera, microphone or messages. A file that differs on any of those is not the official build.
Can I install an older version over the current one?
Not directly. Android will not install an older version over a newer one, so you have to uninstall first. Your account is stored against your mobile number, so nothing is lost.
Will I lose my balance if I uninstall?
No. The account and the balance live on the operator's servers against your registered mobile number, not on the handset.
Do I need to update the app manually?
No. The app keeps itself updated and notifies you when a new version is available, so there is no version number to watch and no page to check.
Is it safe to use an old version?
It works until it does not. Security fixes stop arriving, and server side changes eventually break older clients. It is a reasonable short term move for a specific bug and a poor long term position.
Where can I get an older build safely?
Ask support. Downloading a labelled file from a mirror means trusting a stranger's copy of an app you are going to put money into.
Play for entertainment, not for income. Jaiho Arcade runs on real money and every game in it is built to return less than it takes over time. Decide what you are willing to lose before you deposit, set a deposit limit in the app, and stop when you reach it rather than when you feel like it. Online gaming is regulated state by state in India, so check what applies where you live before you play. If it stops being fun, the app has a self exclusion setting and there is free confidential help available. For industry context, the All India Gaming Federation is the trade body representing online gaming operators in India.