They are totally 2 different courses and streams. It is upto your interest.
Btech is the 4 year full-time undergraduate course leading to the engineering degree. The duration of undergraduate engineering course varies from country to country. Many colleges/Universities of India offers B.Tech programme in various disciplines.
Some of them are:

Computer Science and Engineering
Information Technology
Electronics and Communication Engineering
Electrical Engineering
Mechanical Engineering and more..
If you are interested to study more in this field then you can go for higher studies. You have the option to purse M.Tech after B.Tech. Master of Technology (M.Tech) is the advancement in this field through which you are particularly specialized in one area. Some candidates also choose MBA after B.Tech. One can also opt teaching field and become professor after M.Tech.
BPharma
Getting a job directly after B.Pharm is little troublesome, if you're not looking for job in sales and marketing and want a career in research or some other job then you'll have to pursue higher studies. Students interested in academia and R&D take up M.Pharm or Ph.D. It will not only add a higher degree and greater career opportunity to your CV but also you can become a professor in Indian universities.

Career options are:

Pharmacist
Drug Inspector
Drug squad in police department
Technician in college
Medical underwriter
CRO
Data validation associate

So accordingly you can choose the career you are interested in.
good Luck.