He has, since retiring, opened his own gym, the M-16 gym. He is the nephew of the former Rajadamnern and WMC champion Tappaya Sit-Or and the cousin of the reigning Thailand and World Kickboxing Network Muaythai Welterweight world championSudsakorn Sor Klinmee. It was his uncle that first introduced him to Muay Thai.
Rambaa Somdet made his mixed martial arts debut against Takumi Yano in 2001 during Deep 3 Impact. He won a unanimous decision. His second and third fights with DEEP were against Mitsuhisa Sunabe and Darren Uyenoyama, both of which he lost by way of unanimous decision. Somdet would however leave the organization on a win, defeating Takeyasu Hirono. He would then move to Shooto, when he faced Takehiro Harusaki during Shooto: Battle Mix Tokyo 4. He won in his debut with Shooto. In his second fight he faced Masaaki Sugawara, which he won by TKO. He was then set to fight Noboru Tahara, winning his third fight in a row. Briefly leaving Shooto he was schedule to fight for the PFC flyweight title, but was forced to withdraw with injury. After recovering he faced Ulysses Gomez during. He won a unanimous decision. Riding a five fight winning streak, he was given a chance to fight for the inaugural Shooto Flyweight Champion. Somdet defeated Noboru Tahara in a rematch to become the first Shooto Flyweight Champion on November 23, 2009 in Tokyo. He defended his title against Hiroyuki Abe. He was scheduled to defend his title against Junji Ito at "Shootor's Legacy 2" on March 12, 2011, however the bout has been pushed back to April 29, 2011. On April 16, 2011, Shooto announced Somdet was vacating his title due to a partially torn left biceps. Moving to GRABAKA he won a decision versus Takuya Eizumi. Following this win, he was signed by PXC. Is his first with PXC he faced Rabin Catalan. He won the fight with a rear naked choke, the first submission win of his career. Returning to GRABAKA he won a unanimous decision against Kenichi Sawada. His 11 fight winning streak was snapped at PXC 46, losing a close split decision to Cristiano Pitpitunge. His last mixed martial arts fight came at Shooto - Torao 15, when he won a unanimous decision against Masayoshi Kato.
