B.Tech

Visit the link mentioned below:
https://engineering.shiksha.com/distance-learning-engineering-in-Kolkata-categorypage-2-58-1-0-0-130-127-2-0-none-1-0.

At the 2015 year endings, new government allowed B.Tech Distance. Go through the subjects and study methods, choose a university.

No, it will be approved by UGC (University Grant Commission). For more, visit college's official website or call on their helpline number.

Yes, you are eligible to get admission for B.Tech lateral entry in Guru Gobind Singh Indraprastha University. Good luck for the future.

List of best colleges in India for mechatronics are:
1. Thapar
2. Sastra University
3. LPU
4. Chandigarh University
5. MIT.

Many colleges provide part-time courses, so you need to filter out the colleges which you found great and apply for the course of your choice.

Yes, various colleges have an option of distance learning where you can do your course just by sitting at home. So, yes, you have a good chance to pursue the course of your desired choice.

Yes, you can try through state university academic committee through admission.

The only drawback of BCA+MCA over B.Tech is that you will have to spend 1 extra year in BCA+MCA but I would suggest you to go for BCA+MCA because it makes your fundamentals strong if you are not from computers background. Also, there is less unnecessary pressure and workload in BCA so that you can focus on your skills better. As far as salary is concerned, to an exceptionally skilled person there is no limit. But even if you are sound at coding and have some good logic then your minimum salary will start from 25k to 30k and with your skills, your salary will increase exponentially.