Hello Rahul Kumar Ram.

With a ranking of 6000 in wbjee , if you belong to Schedule Caste then you can get Chemical Engineering at the end of round 3 of counselling.

With a ranking of 6000 in wbjee , if you belong to Schedule Tribe then you can get Chemical Engineering at the end of round 1 of counselling itself.

Since it was not metioned which schedule category you belong, i mentioned both.

For both the categories you can easily get Power Plant engineering in first round.

Hey there

You have a decent rank in schedule category so you will get chemical, power infact you have fair chances of getting CSE in Jadavpur University Kolkata.

Check wbjee cutoff

https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/articles/wbjee-cutoff/amp&ved=2ahUKEwjsgf2zo4bjAhX18XMBHaB_B50QFjAEegQIBBAB&usg=AOvVaw0oKi3F5JzAbrtqB4WCCTEk&ampcf=1

Good luck