Hello Ayan, based on the JOSAA closing ranks of the final round of 2018, you have a very high chance of getting CS branch in IIIT Hyderabad(Closing rank marks was 256 which is around 1300 rank), You can easily get top NITs like Trichy and NIT Warangal. Check the 2018 JOSAA last round cutoffs to finalize your course and marks:

2018 JOSAA last round Cutoffs: https://josaa.nic.in/webinfocms/Handler/FileHandler.ashx?i=File&ii=139&iii=Y

you will definitly get CS branch in IIIT Hyderabad and all other top colleges through jee mains(Except IIT)