I have got 61 percent in my b.tech and now I can't determine what to do next
There are many options available for you after completing your B.Tech degree.
If you are interested in higher studies you can go for M.Tech. If you have interest in management you can go for MBA.
There are many diploma courses as well which you can opt for.
If you want you can also go for civil services exam. You can also go for Indian Army/Navy/Air force.
Good Luck!!