Hello Nikhil,

The cut off is different for  different branches.According to JEE Advanced 2019 the cut off ranks for OBC category in various IITs are given below :

IIT Bombay :

Aerospace Engineering : 1330, Chemical Engineering : 1118, Civil Engineering : 1208, Computer Science Engg :37 ,Electrical Engg : 175 ,Mechanical Engg : 477, Environmental Science & Engg : 3012

IIT Delhi :

Engineering Physics : 1631, Chemical Engineering : 1242, Civil Engineering : 1329, Computer Science Engg :65 ,Electrical Engg : 295 ,Mechanical Engg : 606, Textile Engg : 3258

IIT Guwahati :

Chemical Engineering : 2343, Civil Engineering : 2382, Computer Science Engg :288 ,Electrical Engg : 844 ,Mechanical Engg : 1358, Electronics  & Communication Engg : 744, Biotechnology : 3971, Engineering Physics :2419

IIT Gandhinagar :

Chemical Engineering : 3182, Civil Engineering : 2872, Computer Science Engg :616 ,Electrical Engg : 1636 ,Mechanical Engg : 2263, Material Science & Engg : 4030

IIT Madras :

Aerospace Engineering : 1471, Chemical Engineering : 1594, Civil Engineering : 1690, Computer Science Engg :83 ,Electrical Engg : 336 ,Mechanical Engg : 846, Engineering Physics  : 1304

IIT Roorkee :

Biotechnology : 3358, Chemical Engineering : 1990, Civil Engineering : 1992, Computer Science Engg :195 ,Electrical Engg : 720 ,Mechanical Engg : 1084, Metallurgical and Materials & Engg : 2978,Electronics and communication Engg : 567, Engineering Physics : 2162

IIT Kharagpur :

Aerospace Engineering : 1651, Chemical Engineering : 1743, Civil Engineering : 1813, Computer Science Engg :119 ,Electrical Engg : 598 ,Mechanical Engg : 921, Instrumentation  Engg : 1135, Industrial Engg :2019

IIT Hyderabad :

Chemical Engineering : 2225, Civil Engineering : 2364, Computer Science Engg :287 ,Electrical Engg : 859 ,Mechanical Engg : 1260, Engineering Physics  : 2378,Artificial Intelligence : 368

IIT Kanpur :

Aerospace Engineering : 1717, Chemical Engineering : 1550, Civil Engineering : 1787, Computer Science Engg :133 ,Electrical Engg : 556 ,Mechanical Engg : 890

IIT Ropar :

Chemical Engineering : 3501, Civil Engineering : 3350, Computer Science Engg :1010 ,Electrical Engg : 2218 ,Mechanical Engg : 2828

There are 23 IITs in India.The cut off varies according to the branch.The cut off ranks for some of them are given above.You can know more about the closing ranks in the link below :

https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iits

Hope this helps!!