Hello Kampobhaskar.

During first year B-tech course content for all branches is same and it is 80%what we studied in 11th and 12th.

You need not to worry too much like.

In maths it is partial derivatives and (calculous) Matrix etc.

In chemistry it's chemical bonding isomerism spectography.

In electrical dc machine Transformers Etc

In electronics it is transistor and semiconductors etc.

Similarly in remainings.

Ok