RPC List - katursis/Pawn.RakNet GitHub Wiki
All the types of variables which are given there can be translated as:
INT8,INT16andINT32=>PR_INT8,PR_INT16andPR_INT32UINT8,UINT16andUINT32=>PR_UINT8,PR_UINT16andPR_UINT32float,bool=>PR_FLOAT,PR_BOOLchar[],CSTRING=>PR_STRING,PR_CSTRING