The Mary Mitchell Center, Bronx Health Reach and the League of Conservation Voters are co-sponsoring a forum for candidates of the 15th Council District tonight, from 6:30 to 8:30 p.m. at the Bronx Library Center, 310 E. Kingsbridge Rd. The 15th Council District, currently represented by Joel Rivera, includes the neighborhoods of Fordham-Bedford, Fordham, West Farms, Tremont and Crotona. There’s at least a half dozen candidates vying to replace Rivera, making this the most wide open and unpredictable race in the Bronx this summer. Tonight will be a good opportunity to find out who’s who and what they stand for.