Mechanical Engineering

See, the best option is to first study mechanical engineering, and then do one year additional marine engineering. See, you will have vast scope of jobs. You can work on ships or you can work on cars. The choice will be completely your's.

Yes, it is good.
Only if you focus on what you are taught and apply it in the labs provided.
That was the key for many outstanding students of CU mechanical branch alumni.

If you are in category like SC, ST, OBC, then you will surely get best college in Pune. Some colleges are:
Dr. D. Y. Patil Vidyapeeth
MIT, Alandi
JSPM

After HSC, you will have to sit for entrance exams for colleges. If you want to get into one of the prestigious colleges like JEE, BITSAT, IPU-CET and there are many other. You will get a college for engineering according to your score in the exam.
Good luck.

Please check the college details by visiting the link mentioned below:
https://www.shiksha.com/b-tech/resources/mhcet-college-predictor

My advice is that you should join G L Bajaj Institute of Technology And Management. It is one of the best colleges of AKTU. You have good study environment here. Well qualified professors are here.

Yes, you can get admission in Galgotias University to pursue the 2nd year of B.Tech through lateral entry.

First of all, the job got by an ITI student and a Diploma student is same. There is hardly any market for this and your salary can be as good as Rs. 10000 to 15000 per month. When you do mechanical engineer, you may get job as assistant, technical assistance, technician, and operator in manufacturing set up however you will not get growth in the career unless you have an engineering degree. If you do computer science Diploma, you may start own business of computer service and repair or may get job in similar field, again no growth in the career without a degree so choose only if you are planning for a degree else better go for ITI.