See at this stage, I suggest strongly you go for b tech after completion of 12th other than going for diploma. That would be rather a waste of year which wouldn't benefit you. There is a good scope for b tech students if you have good knowledge and communication skills. So just don't worry and go with the flow. Be firm with a strong decision that yes you will surely excel in this flow and see how success pays if you really work hard.

Hello ansh sharma,
It would have better if you taken the diploma after your 10th. But still if u want to do the diploma in mechanical engineering you can do it after your completion of (11th & 12th). But think once before you are going to do that. After completion of 12th it takes only 4 years to complete B. Tech but if you want to do diploma and later btech then it takes              [3(diploma) +4(btech)] years. If you want to do only diploma you can do it after your 12th.But if you have a idea to do B. Tech after your diploma then i suggest you do the B. Tech after your 12th. Take a right decision at the right time.
All the best...