Kotak, who begun his career against Bombay in December 1992, has played 129 matches so far, scoring 7996 runs at an average of 41.64 and 15 hundreds.
Kotak, who will turn 41 tomorrow, said he wanted to retire after Saurashtra reached the Ranji final last season but postponed it in the emotion of the moment.
"I felt the team had done so well to reach the final," he said. "It was a superb achievement and I did not want to take away from it with talk of my retirement," Kotak told ESPNcricinfo.
"To have played for so long and not be dropped, I could not have asked for more. I would like to remain associated with the game in whatever manner possible after retirement," added Kotak, who also took 69 wickets in his career.