How to defend a false rape case

Mere ek friend ki girlfriend ne uske uper case kr diya h ki wo uska educational documents le liya jabardasti or fr usko de ni raha or uske sath wo rape kiya or video bna kr blackmail kr raha h.. Ye sab jhuth h wo ladki jhuth bol kr usse fasa rahi h or jb wo FIR ki tb police bina kisi investigation ke uss ladke ko arrest kr liya or tin months tk jail me rakha bina ladke ko investigate kiye bina warning ke ye sb achanak se hua bs ek written application pe... Iss situation ko ab uss ladke ko kya krna chahiye kyuki ye case to false h wo ladki apni marzi se thi uske sath or physical relationship tha dono adult h to fr ye case kaise valid h please let me help and suggest me ki ab uss ladke ko kya krna chahiye...sir wo ladka av bail pe jail se nikla but ab kya kre ki pura case khatm ho jaye FIR hote hi uski arresting ho gyi or 3 months usko jail me rakha gya 19 th October ko jail hui thi usse