He then joined Jadavpur University as professor and founder head of the Department of Construction Engineering at its new campus at Salt Lake, Calcutta.

He was also conferred the degree of Doctor of Letters (Honoris Causa) by the Shri Jagdishprasad Jhabarmull Tibrewala University, Vidyanagari, Jhunjhunu, Rajasthan, at a special convocation at Mumbai in May 2016.

He was further conferred the degree of Doctor of Engineering (Honoris Causa) by the National Institute of Technology, Agartala, Tripura, at the convocation in November 2016.

He replaced Ashim Ghosh as president of the West Bengal state unit of the BJP in 2002 and was succeeded by Sukumar Banerjee in 2006.

[5] Roy stood as a candidate for election to the Lok Sabha in 2009, standing in the North Kolkata constituency of West Bengal.

[8] He served till December 2019 and, after a brief medical leave, again from January 2020 until 18 August 2020 completing his five-year tenure on gubernatorial post, handing over the charge to Satya Pal Malik.