Atuloma put pen to paper for a 2-year deal with the club, and he has option for another year, but renewal depends on his performance.
The experienced playmaker was on the book of former Nigerian champions Heartland FC last season, but moved on after his contract came to an end.
He became the latest player from the domestic league to complete a switch to Asia in the last 24 hours, after Mfon Udoh who joined Bangladesh side Saif Sporting Club Limited.
FC Al Rustaq are 9th on the Oman’s Premier League with four points from possible twelve.
They lost suffered an embarrassing 4-0 defeat FC Dhofar in their last league game.