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.