NIT

Yes, you can get NIT for ECE. You can try the college predictor in Shiksha. However, some colleges you can get are:
1. NIT Srinagar
2. NIT Tripura
3. NIT Itanagar
4. NIT Srinagar, UK
5. NIT Aizawl
6. NIT Dimapur

No, NTA will not officially announce cutoff ranks for different categories.

Lots of comparison are there:
NIT is brand UIET is just formality in NIT from this year for first year students there will be a subject called Machine Learning and in UIET there is Biotechnology which is no useful in field of Computer science.
There will be extra clubs for training in coding and to build some extra skills but in UIET, you were taught by teacher only from syllabus and which is also not tsp good.
So, I prefer the studies of NIT, rather than UIET.

First of all congratulations this is a good rank.
But unfortunately you cannot get into top nits
But do not worry you could try for better IIITS
Best of luck

I guess you would not be able to ge into good nits but you could try for IIITS
Best of luck

Do not worry you have got a good score
But unfortunately you do not have chance to get into good nits but mostly you have a little chance of getting into north east nits,
And even you can try for IIITS
BEST OF LUCK

No, you don't have a chance of getting into top NITs. You have a chance of getting into NIT-Silchar and NITs of north east.

NIT seems difficult with this rank, but there are some of the good private universities where your son can get nice branch of study with his rank like Chitkara University etc.

To get into IITs you should get through JEE Advanced. With your given percentile I wish you would get into any IIITs.