solutions for these ipc u/a

hello..my brother/sister is accused for a case under ipc 186/353/332/506/34 .. as a matter was between him/her and mcd je + police constable..while his house was demolishing by mcd je.. the case is been Proceeded from last 4 years in tees hazaari court.. chargesheet is been filed. now evidences r going on. how can i support him to get the case squash.or dismiss.. do the complainant got power/right to take the case back??