Mechatronics Engineering

mechanical is better

Amar go for your degree. After diploma you will get admission in 2nd year.of B.Tech also called lateral entry.
For lateral entry, you have to appear for Lateral Entry Engineering Test (LEET). You must have min.of 60% marks in diploma to appear for LEET.
If you have not given LEET, then opt for good private universities. They offer world class environment to students along with good placements. Some even offer good scholarships to students. Check their websites.
Good luck.

NIT Mangalore is the best college

VIT University (VIT)
SRM University, Chennai (SRM Chennai)
Anna University (AU Chennai)
Netaji Subhas Institute of Technology (NSIT)
Manipal Institute of Technology (MIT Manipal)
National Institute of Technology, NITK, Surathkal
Acharya Institute of Technology (AIT Bangalore)
Amity University (AU Noida)

Off course yes. It's very competitive too. The university provides scholarship options as well in case you are looking into it. One of my undergrads students is studying there and is extremely happy with support and academics both

Dear Manan, in addition to Ms Pallavi, I wish to add that you must score high academics & develop good repo with teachers who generally can recommend you for jobs. As Canada is a PR oriented country with lots of job prospects but of course how well you communicate/demonstrate your knowledge earned is going to fetch you a job.

Mechatronicsis a multidisciplinary field of engineering that includes a combination of systems engineering, mechanical engineering, electrical engineering, telecommunications engineering, control engineering and computer engineering. It has very bright future in India.
I have no idea about colleges in Pune sorry.