Dear Jack Dawson,
First of all IIT's brand name is more good than the NIT's..and then coming to IIT guwahati you will have more broad exposure than the NIT's..and if you compare three colleges are very good..placments are really very good in all the three colleges but IIT is IIT and NIT is NIT..so as per me if you get IIT (old) then go for it than the NIT warangal or trichy bcoz my friends so many join in NIT waragal even though they got in IIT (old) after that they realised that they did a wrong step..so please choose good on and go for it.
Please feel free to post as many doubts on our discussion forum as you can.
If you find any question Difficult to understand - post it here and we will get you the answer and detailed
solution very quickly.
We are all IITians and here to help you in your IIT JEE & AIEEE preparation.
All the best..