Design

NIFT is a premier academic institute of design, management and technology, with aims at establishing benchmarks for quality of professionals that go into the fashion industry. The Institute provides comprehensive and state of the art infrastructure and equipment to impart both practical and theoretical training.
So in my opinion if you are not satisfied there than immediately plan to shift from there. The registration process of NIFT will starts in the last week of this month. Hence plan accordingly.

Nope. A B.Com student is not destined to do Masters in design but in case he possesses enough knowledge about the same and also sufficient marks above 60 percent then he can apply.

You can go for Graphic designing and VFX. There are many opportunities after creating our own portfolio. You can be a freelancer. Post your creative portfolio in dribble and balance to get lot of opportunities.

Not always a great idea to switch education streams radically extreme directions, however if it is your passion go for it. Most of the jewelry design courses are skill courses and mostly anyone with an interest in the field can go for those. However, if you are looking at a serious career in the direction of finance (since you are a commerce graduate), I can recommend 2 courses which can help you make a distinct career for yourself.
Career opportunities include Big4 (Deloitte, KPMG, PwC, E&Y), top global audit firms (BDO, Grant Thornton), US MNCs (Accenture, Cognizant, Genpact) and many Indian MNCs listed in the US markets.

Since you have got more than 60 percent in your boards hence you are eligible to sit for the NIFT entrance test. Depending upon your score you will be alooted a NIFT branch.

Drawing is a very vast field that consists 2D or 3D representation of an object. The course about which you have asked can be the right choice for you, if done from the right institute. I am suggesting here a few entrance exams, which can be helpful in refining your hidden talent.
1. Undergraduate Common Entrance Examination for Design (UCEED)
2. National Institute of Fashion Technology (NIFT)
3. National Institute of Design (NID)

The minimum eligibility criteria is that you have to be 10+2 passed. You may take direct admission because there is no official entrance exam conducted.