is it advisable to opt btech in cs in such recession time??or go to core fields like mechanical,petroleum,etc

Hi

Recession time is not for the lifetime. it surely will end , a year or more later, and moreover recession is not just for cs, its for all the sectors coz all the companies depend on economy. Ironically, cs has been placed much better than mechanical this year too.

Also, tll the time u graduate the market will be stable, and cs wont be a bad option.