Hello both are top engineering collages with AAAA+ grades the fee structure at Thapar is around 11.4 lakhs and VIT has an fee structure of 7.8 lakh, Thapar is AICTE Approved but VIT is UGC approved, Thapar accepts JEE Mains, TIET B TEch Ad,issions where as VIT accepts NATA, both are NAAC A grade accreddited, VIT has a good placement record with an average package of 4 to 5 lakh PA with popular organisations such as Accenture, Wipro, Cognizant, Infosys and it has enterd thrice into Limca Book of records for highest number of placements were as thapar has placed its students with an average salry package of 5PA and the companies visiting are Infosys Sandisk Amazon D shaw etc.. since your home town is delhi and Thapar University Patiala is nearer you will be near to home town but Vellore is a cvast cultural dimensions students from all the parts of India come here to study so if you want to experience a different culture then opt for VIT but choice is yours choose wisely. All The Best For Your Future. 

Thank You