Hi Nitish S.

All these 3 colleges are really good. So, if you get any of them, you can go for it. But, in my opinion, PSG is the best choice in these 3. It is because, the placements, the campus life, the faculty etc. are really good here. This doesn't men that the other 2 choices are bad. What you have to do is, go through reviews of students from these 3 institutions and get to a conclusion. I suggested PSG because it's one of the best colleges in India, and core placements there are better.

PSG - https://engineering.careers360.com/colleges/psg-college-of-technology-coimbatore

SSN - https://engineering.careers360.com/colleges/sri-sivasubramaniya-nadar-college-of-engineering-kalavakkam

SASTRA - https://university.careers360.com/colleges/sastra-university-thanjavur

Just check these pages where you can find ratings, reviews and all about these 3 colleges.

Good Luck.