sir i have got 182 marks in iit advance and 322 marks in bits? can i expect mechanical in old iit or should i go for bits?

Your expected rank in JEE is 3800.I think you can get mech at IIT Mandi and IIT Ropar and electrical at IIT Hyderabad.You will get CSE at BITS Goa and Hyderabad.At BITS Pilani you will get BE chemical,BE manufacturing and Msc+BE(dual degree).Join an IIT for the IIT tag.