My brother had the option of VIT for CSE on merit still he chose PEC metallurgy. There are various reasons as to why he took that decision:

• VIT is more expensive. Even if he had gone on merit, it would have cost him much more than PEC.
• Placements in core companies in ECE are negligible. You can sit for IT companies, but they pay less to ECE undergraduates than CSE counterparts.
• If you are a north Indian, culturally VIT might be different and might take time to adjust.
• Metallurgy is an undervalued branch in India; many of my seniors are pursuing MS from Germany, the United States, and France, and some have gone to IIMs and FMS with strong credentials.
• One of our seniors received a PPO of 15 lakhs, which is more than many students from elite branches.
• You can choose to upgrade, but you'll quickly realize that it's not that simple because the grading criteria favors those who are less deserving (no offense).
• Whether you accept it or not, those who claim that placement in metallurgy is poor (as it is in all branches except CS/IT) are correct. Placements in the core are hard to come by.
• Only 4000 people in GATE are from metallurgy, whereas there are 1.8 lakh from CSE and 2.1 lakh from Mechanical, implying that the probability of you getting a PSU is greater than that of a mechanical engineer.

I personally believe VIT is overrated because a friend who did not even pass mains received 2000 AIR in VITEEE. In the CBSE 2016 boards, he scored 78 percent, which was below average.

One of my cousins studied at Maharaja Surajmal Institute of Technology (MSIT) and he never bought a single book for any branch.

You will get free access to all the books from the book bank. You will also get personal textbooks each semester as soon as you get your college IDs. There is an online portal available that helps in getting ideas about the books available in the book bank.

You will be required to pay for the book bank that has already been added to the college fee in the first year.

There is a book store outside of MSIT where students can buy books of Bhavya Publications which are easy to read and understand and written in simple language. It helps in scoring good marks in IPU.

It is suggested that you choose the institute that is in close proximity to your location, since both the institutes are rather tier-3 Indian Engineering Colleges. 

• The major similarity both Goa Engineering College and NIT Goa share is that fresh graduates often go on to become clerks at several service based companies. 
• They often get an average salary package ranging anywhere between 3 LPA to 4 LPA.

In any case, nobody can apparently have access to the actual placement report of either institute because most of them generally spike their records for unjust purposes. Yet, here is a detailed placement statistics, as is claimed by the institutes in general.

Indian students generally should enroll at colleges near to their residence. And later start to impel the administration to offer basic amenities, if any missing, thereby gradually incrementing the possibility of them obtaining industry relevant skills. Your placements and overall college life has to provide you with the necessary facilities, only then you can grow as an individual.

It depends on where you want to live and study. If you are comfortable staying in Pondicherry and are interested in ECE, go with PEC, which is one of India's oldest institutes.

On the other hand, SASTRA University is a more recent private prestigious university and it has great infrastructure facilities and placement record. BioTech in Sastra has IT placements with a lot of companies whereas ECE in PEC has good placement but is not that great.

The table shows a brief overview of the institution:

You can opt for PEC as its fee is lower than SASTRA. However, go for it only if you are getting a seat in ECE. If not, SASTRA can be considered as a final option.

Yes, they are enough but only if you do not miss a single class, and are very serious about every assignment and internal mark.

Your professors and seniors would definitely suggest you the reference books and you should their advice. Everything is not about marks. You should have surplus knowledge about your subjects which brings completeness into the course. 

Due to time limitations, everything cannot be taught in the class. Also, engineering is beyond your semester syllabus.