Colleges in Tamil Nadu

From this, three.
According to me DAIICT, Gandhinagar and VIT are best for M.Tech. You can choose according to your criteria.

Yes, many universities offered through distance and here is an availability of seat in Suresh Gyan Vihar University, Jaipur. You can contact them. All process is online and no problem to do from this university.

As the fee is not disclosed by the college officials, I would request to contact the college as they will be in a better position to help you.
Link to get contact details: http://www.annamalaiuniversity.ac.in/dde/

Yes, of course, it is.

Yes, of course, you are eligible for B.Ed but go for regular instead of distance.
All the best for your bright future!

The best private colleges in Tamil Nadu are:
VIT University, Vellore
SRM University, Chennai
PSG College of Technology, Coimbatore University of Technology
Amrita University, Coimbatore
Madras University of Technology
Karunya University Coimbatore
Sastra University, Thanjavur
SSN College of Technology, Kila

I think, targeting SRM is not worth, as the value for MBA is only into good B-Schools. I'll suggest you to give CAT once again.

Hi Ravi,
Yes, on completion of the Diploma course, students can opt for a Bachelor's Degree in Mechatronics Engineering. Most Diploma degree holders take admission into an engineering college through lateral entry. Am not sure if it can be done part time though. Hope the answer helps to an extent.

Please visit the link to know about the fee structure:
http://vit.ac.in/admissions/ug/feeStructure

Yes, VIT University is good to pursue engineering, especially its Vellore campus is very good and has a good placements and academics records. Vellore comes under top 10 engineering colleges in India. But don't go for their Bhopal or Amravati campuses, they are newly opened campuses (opened in 2017)