A stepdown transformer should be all you need, with the following caveats:
If the unit incorporates synchronous motors for a tape deck or turntable, they will run at 5/6 speed.
If the unit incorporates a digital synthesized tuner, the channel spacing and/or frequency coverage may not match the Indian broadcast allocations.
Running a 60 Hz power transformer on 50 Hz will generally cause the transformer to run a bit warmer than usual. Whjether this is a problem or not depends on the transformer design.