In no particular Order,the cheapest engineering colleges with atleast decent placement and infrastructure-

1.Jamia Millia Islamia -Nice placement and quite good infrastructure. Fees --> 28K for 4 years Btech

2.CIC DU- Not a college infact,Its innovation Centre where innovative and real life engineering is promoted.Fees--> 12K per annum.Yes you read it right.

3.Govt colleges of IPU-

i ) USICT-Quite Good placement,Good infra at a cost of 55K per annum

ii ) GB PANT Engineering College- Poor Infra.Okayish placement.Fees- Around 40K per annum I guess AIACTR(Another college of IPU) has better infra and better placements(Better then GBPEC) with same few structure.

Some of the colleges provide scholarships too or discount.But I did not mentioned them.

Hello Rahul,
According to lets intern survey
These are the colleges considering your priorities and having AAAA+ rating.
1. PSG College of Technology, Coimbatore.
2. Shanmugha Arts, Science, Technology & Research Academy (SASTRA University), Thanjavur.
3. Thiagarajar College of Engineering, Madurai.
4. College of Engineering, Guindy, Anna University
5. Amrita School of Engineering, Coimbatore.
Thank you.