False fir in 326b ,administer to throw acid

My brother made a complaint against a school for which an inquery has allready been done by DC of our city and it was in his favour.. To take revenge from my brother school teachers made a false complaint against my brother at 11/8/2016 ,at that day an ASI called my brother in PS , we went there but he did not took his statement , we went PS next day also but they refused to take his statement again so we send his statement through registered post to SHO on 13/08/2016 that this is the false complaint in which school and teachers are included .we thought that police will definately call us after that for an inquery, but no .after that police file a FIR on 17/08/2016 under section 154 cr cpc of 326b,506,511 ... This is truely a false fir against my brother for which school managment is responsible..my brother has a lot evidences that school management is making frauds and he has also some call recordings which can prove that this is a false complaint , copy of registered statement which he send to SHO and school managment is culprate ... Plz suggest the best we can do ... Thanks in advance ..