Nigerian star Bart Ogbeche, who claimed an ISL double recently, completed his move to Hyderabad FC earlier this week.
Boumous has signed a five-year contract with the Green and Maroons which will keep him at the club until 2026.
Two-time Indian Super League (ISL) champions Chennaiyin FC (CFC) have signed goalkeeper Debjit Majumder ahead of the 2021-22 season.
Indian national team goalkeeper Amrinder Singh joins ATK Mohun Bagan after leaving ISL champions Mumbai City FC.