Diploma

Hello Spandana,
If you are thinking of lateral admission then answer is no. Lateral admissions are allowed only in related subject.However, if you treat diploma as equivalent to 12th, then you can join IIT also in first year of any subject.

Diploma-holders in engineering are not eligible to do MBA until they complete graduation degree in any discipline.

National Academy of Indian Railways, Baroda runs training programmes for Indian Railways officers of all disciplines and all grades right from Probationers to General Managers. It does not offer courses directly like an engineering college or polytechnic or management college.

You should have completed 12th. Then only you will be eligible for this degree program.

Yes, absolutely, you can go. But you should fit in the eligibility criteria of the college that you are interested in.
Check the eligibility criteria and admission process.