Will campus come n select the btech biotechnology students in final year n if they select what will be the salary

Campus won't come,companies maybe. Better you mention the college/university you're talking about.

Most of the universities make efforts and provide opportunities for placements. Companies visit campuses for recruitment. On an average, B.Tech biotech.students tend to get 4-7 lacs package at the start of their career. This varies from university to university. Check with some good reputed universi