Even an open platform would do nothing. If you are a suspect, your phone would be checked in person (India doesn't have the concept of the 4th Amendment, and police demanding physical access to your phone during a search is routine) and if you were using something like GrapheneOS, it would be used as evidence against you. Indian law enforcement has already used access to Signal and Telegram as circumstantial evidence in various cases, and it's a simple hop to create a similar circumstantial evidence trail with someone using GrapheneOS.

And anyhow, major Android vendors like Samsung have aligned with the policy as well.