TOEFL

National university of Singapore and Nanyag Tech Universities are the top most universities of Singapore.
All the best for your bright future.

GRE is an examination conducted for admissions into various colleges and universities in US. It primarily tests your reasoning ability. GRE score is considered by top colleges. TOEFL is an examination conducted primarily to test your English. TOEFL score is compulsory for education abroad. If not TOEFL, IELTS will be compulsory.

Yes, most of the universities in London accept TOEFL score.

Yes, you can. The scores have a validity of more than 1 year. So, you should be able to do so.

No, without this also you can do MBA. If you apply for freshers MBA in the UK, there no need of GMAT or GRE. If in your class 10th and 12th exams, you scored more than 70% in English, you can get an exemption for IELTS or TOEFL.

Do you want to study abroad or work abroad after studying in India? For the latter part, I would suggest complete your PG by either M.Des or MBA. Both have a good demand in foreign nations. Also give IELTS or TOEFL exam and check colleges that will give you admission based on your score for studying abroad.

Hi there!
No, Indian universities don't accept IELTS, TOEFL, SAT or ACT. These are usually used for taking admission in foreign universities.
Hope you got your answer.

Hi,
I can talk for IELTS. In my opinion, give it a good 3 months preparation time. Do a regular practice and be consistent. You can actually clear on your own.
1. Enroll in a lot of free courses online like on future learn. There are so many websites like IELTS buddy, IELTS advantage, IELTS Liz etc. to get tips and tricks. There are you tube videos too for visual demonstration.
2. Get Barron's and Official IELTS Cambridge books, I personally think they are very good. Follow them regularly and solve all papers.

Yes, you can apply. While processing, the score is valid. They will consider. You cannot apply after 13th August.

In America, TOEFL is a good exam. The USA has its own criteria for selecting the student. Some countries take students without GRE, but in America many colleges prefer GRE, so if you really want to study in the USA, go through TOEFL and as for scholarship, I will suggest you to focus on the admission now.