Yes. Admitted students will receive scholarships according to CSIR/UGC norms. Currently, Junior Research Fellows in Science (i.e., the first two years of your Ph. D.), get Rs. 25,000/- per month, and Senior Research Fellows in Science (next three years) get Rs. 28,000/- per month.
It depends. One can in principle, complete the requirements of a degree in about two years, but this is very rare. On average, it takes about 4 to 5 years. At most, a student might take 6 years. Also, please remember that Ph. D. is not like any other University degree. Research, by definition, is the study of the unknown. This is why one cannot put an exact timeframe (as in, say, that a B.Sc. degree takes 3 years to complete) for a Ph. D. work. The duration we have provided here are good estimates.