As you want to get the details of career after B.Tech in Biotechnology so here is the information of the same for you:

Jobs after B.Tech Biotechnology in India:
Some of them are:

All India Biotech Association (AIBA)
Biotech Consortium India Limited
Rajiv Gandhi Center for Biotechnology Kerala (RGCB)
Amersham Pharmacia Biotech Asia Pacific Ltd.
Brain Wave Bioinformatics Ltd., Chennai
Aristo Pharmaceuticals Ltd., Mumbai
Catalyst Pharma Consulting , Mumbai
Excel Industries Limited, Mumbai
Sisco Research Laboratories Pvt. Ltd., Mumbai
Hi Tech Bio Laboratories, Pune
Ranbaxy
Cipla
Hindustan Lever
Biocon
Torrent
L&T

Areas where B.Tech Biotech students can work:

Waste management
Public funded Laboratories
Chemicals
Bio-processing industries.
Public funded laboratories
Energy
Environment control
Food processing
Drug and pharmaceutical research

Jobs are available abroad in the area of:

Microbiology
Medicine and Health Care
Industrial Research and Development
Agriculture and Animal Husbandry
Environment