B.Tech Computer Science and Engineering

You will have to qualify the entrance exam JEE Mains or college specific exam. You should have atleast 50% marks in 12th with PCM. CS Engineering is a good option. You can search a job in desired field. One can Do Masters in same field or any desired specialization. You can do MBA. You can even appear in Govt. exams to grab a Govt. Job. You can do B.tech and M. Tech from :
IITs, NITs
Banaras Hindu University,
The Maharaja Sayajirao University, Baroda,
Lovely Professional University, Punjab,
Cochin University of Science and Technology,
PSG College of Technology, Coimbatore,
Jadhavpur University, Kolkata

Yes, you can get the admission in CSE without clearing JEE Mains.

You can refer to the following link:
http://saitmgurgaon.com/about.php?catsid=15&catid=4

Yes, Guru Gobind Singh College of Commerce, Pitampura offers this course.

If you want to join merchant navy, you have to complete a one year course.

After completing B.Tech, I don't think Diploma in hotel management will be good idea. Now, the fees varies from college to college.

It will cost you around Rs 4,82,600 for the entire course.

Amity Noida is good in every aspects. It is one of the best college in the entire Delhi NCR region. It is because in Amity there is International Internship/Training program

There are many private colleges, which takes separate entrance exam and you can also apply for state engineering college's exam like WBJEE, which is for West Bengal. Many colleges take admission through JEE Marks, you can also apply there.