He likes the outdoors and plays tennis and squash.[1][2] He enjoys reading Tolstoy, J. R. R. Tolkien and Upamanyu Chatterjee.[80] Rajan appeared on Siddharth Basu's quiz show Quiz Time, telecasted on the national television channel Doordarshan, in 1985, teaming up with his batchmate Jayant Sinha to represent IIT Delhi.[81][82] He has also participated in various marathons, such as the Standard Chartered Mumbai Marathon 2015.[83]