Hello,
With the category rank you have mentioned ie 3393, there are very less chances of getting cse/IT in top nits. But with this rank you will definitely get north eastern nits like nit sikkim, manipur,mizoram.
If you want these two branches only then you can go for these nits, and you can go for iiit gwalior also in special rounds, it is also a good college
Below link is for jee main college predictor, have a look.
https://engineering.careers360.com/jee-main-college-predictor
All the best!!!