Your question does not make sense. Maps are defined and compiled. Programs then use the SEND MAP and RECEIVE MAP verbs to output and return data with the maps. Transactions invoke programs but do not directly reference maps in any way.
You could, potentially, have hundreds of programs using the same mapset -- although that would probably not make a whole lot of sense since presumably each program would want to display and receive different data from the map. Hence the mapset would be so large that it could hinder CICS performance and would be rewritten into individual map sets and maps for each program.