I am studying my BTech in mechanical engg. after completing my diploma.I want to pursue MBA.Is12th complusory or diploma is valid for MBA?

Well, class 10th and 12th result is necessary for any good business school. After class 12th, you have done Diploma, that will be counted as an additional qualification apart from B.Tech. But major results would include class 10th, 12th and graduation (B.Tech) marks.

Maybe, you get admission or maybe not. It all deepens on the university, in my opinion, you should consult the university.

Hello, Don't worry, you are qualified for MBA. Diploma from a recognised university is equivalent to HSC. So, you do not face any problem. Just try to get good marks and get admission. All the best.