My JEE main rank is 20531 will I get NIT Calicut in the home state quota?

NIT Calicut cutoffs for the Home State students are lower than students of other States have better chances. The cutoffs for the first round of General Category Home State Studentsbis given below

Based on the above table, you can get branches like Civil, Material Science, Production, Biotechnology, Chemical, Engineering Physics, and Mechanical Engineering with your rank in the first round. For better branches like EEE and ECE, you can go for the subsequent rounds. 

Most top rankers go for IITs, BITS, and some other top NITs. So considering your decent rank, you will have a better chance to get admission to NIT Calicut. If you still have any second chances, prepare for JEE Advanced too because your Mains AIR is great and you might even get into an IIT.