I bought an iphone from Apple store in USA,Can I use it in India or i must unlock it.

If you have paid the full price , it will be unlocked for the use with a supported carrier. If the phone says "no service" after you put in the SIM card, it is probably locked to a carrier.

Also. since you bought it abroad, the built in hardware might not support all features in your country, for example LTE networks.

And in case your phone needs to be serviced, you'll have to bring it back to the country of purchase, the warranty for an iPhone is only valid in the country or purchase.

Did you buy the Sim-Free version? This will likely answer your question 🙂

Yes if you buy it with a Contract so therefore you must Request to Unlock the Phone from Carrier that is tge Only way !

Or if you bought a SIM-FREE Version therefore you don't need to do any Unlock !