B.Sc

1. Get strong with your basics.
2. Practice previous year's question papers.
3. Catch the topics that you may have skipped in your B.Sc.

If you want Chemistry oriented jobs and excepting decent pay, then B.Sc. Is not quite enough in my experience and knowledge. Because you may result with an 8 to 10 hr of job which pays you 10k-15k a month. PG Diploma course takes 1 year of time but M.Sc. Takes 2 years of time. M.Sc. Have significantly more industrial value and more jobs opportunities in both the Industrial sector and the Research sector. I recommend you to choose M.Sc. If you have 1 extra year of time and resources. Choose wisely.

Yes, Chemistry has good scope till humans exist.
If you want Chemistry oriented jobs and excepting decent pay, then B.Sc. is not quite enough in my experience and knowledge.
Because you may result with an 8 to 10 hr of job which pays you 10k-15k a month.
M.Sc. has significantly more industrial value and more jobs opportunities in both the Industrial sector and the Research sector.
If you have some special contact or strong recommendation in the Industrial sector then BSc may be enough to manage tasks that require only trained but not logical thinking.

For M.Sc. Chemistry admission in Loyola College, you should have passed your all graduation degree papers with a minimum score of 55-60% in aggregate. Apply online when admission is open (probably after April) on the official website and follow the guidelines mentioned on the website.

Yes,
You can apply for M.Sc. Chemistry.

If you asking for an MSc entrance exam for admission in NITT, then it is called JAM and it is over for this year 2022 and conducted on 13th Feb 2022.

B.Sc. Chemistry takes 3 years,
M.Sc. Chemistry takes another 2 years,
Ph.D. Chemistry takes 3 to 5 years depending upon your research output and willingness. The general eligibility for B.Sc. Chemistry admission is passed in all subjects of 12th grade with Science subjects like PCM. Score as much as possible to get admission easily.

Go with your interest because each of them has its own importance in the industry.
If you have an idea of doing research, then go for the branch which contains your research interest topic.

It's 3 years course and its fee is around Rs 1166 per year.

Yes, it doesn't require deep math skills but you should be strong at basic math like Algebra Trigonometry Calculus (Limits, differentials and Integrals Matrices and Functions.