He was former player for the UST Growling Tigers in the UAAP, the Sunkist Orange Juicers and the San Miguel Beermen in the PBA and the Pampanga Dragons in the Metropolitan Basketball Association.
Other members of the said squad were Chris Cantonjos, Estong Ballesteros, Rey Evangelista, Dennis Espino, Udoy Belmonte, Del Rosario's son Lester and Bal David.
In the 2004–05 Philippine Cup, Tanquingcen once again led the crowd-favorites to its first back-to-back title in franchise history after defeating the Talk 'N Text Phone Pals in six games.
In the 2007 PBA Fiesta Conference, Tanquingcen was sent back to San Miguel as an interim coach for Chot Reyes, who focused his role as head of the Philippine national basketball team.
In a wildcard match against the Coca-Cola Tigers for the final quarterfinals berth, San Miguel won a 102–101 miracle score despite trailing by four points with only 13 seconds left.
Their run continued in the quarterfinals, scoring an upset against his former team, Barangay Ginebra, in the best-of-three series before falling to eventual champion Alaska Aces in a grueling six-game tussle.
After one conference Jong Uichico then decided to move to Pangilinan owned Meralco team as a consultant right after being considered to be part of Smart Gilas coaching staff.
At the start of the second conference Siot becomes the lone coach of the country's most popular team with Allan Caidic, Marco Januz Sauler and Art dela Cruz as assistants.