Hello Aspirant,

If you got 250 marks out of 300 then you can easily get CSE branch in not only IIITs even in NITs also because according to your marks your percentile will be around 99.8 or more and on the basis of this rank you can easily get top NITs like NIT Trichy, NIT Warangal and so on.

But if you want to take IIITs than IIIT Allahabad would be the best choice for you but I would personally suggest you to either go with NITs or with JEE-Advance which can take you to the IITs like premier engineering institution.

However you can use JEE-Main college predictor tool to predict your college according to your category and percentile scored in JEE-Main, link for the same is given below :-

I hope this information cleared your doubts.

Good Luck!!