Is integrated btech + MBA is better or to complete btech from reputed institute then to go for MBA?

B.Tech and MBA would take 6 years (4 years of B.Tech and 2 years of MBA). So it may not be equally valued against a normal B.Tech + MBA. And also you would have to think about what specialization you would opt in MBA, opting Finance/Marketing/HR would clearly contrast your Engineering degree, which will be of no use. So you can choose IT Management/Business Analytics etc.

I would suggest you that the better course of action is that complete a regular B.Tech and get a job. After a few years of experience, join MBA or EMBA with specialization which can help boost your career.