Hi.

I actually don't get waht you're saying. How can you relate your interest towards doing B.Tech and score in JEE Main? It's your decision to choose the course that you like. When choosing one, ensure that it is the right choice. If you choose wrong, it's going to waste a year or more of yours. So, if you want to study for B.tech, go for it. Or any other course, choose one of them, which you like.

Good Luck.