False complaint of rape stating commitment of marriage

A very close friend of mine has been booked u/s 376 in Bihar (though he is from maharashtra). He happens to be a SC person. When the Lady who has lodged the complaint knew about his caste but when her parents came to know, they asked her to deny to marry. Later the parents even kept the boy captive at their place and on many occassions abused his on his caste.

The scenario is such, that the boys' mobile has been confiscated by the police and has been destroyed in order to make sure that the SMS and call recordings do not reach the court. The SMS and Calls are a proof enough to show that the boy has been abused on basis of cast and also a proof enough that the girl had approached him to have physical relations.

I have also read some where about "Consent Based Physical Relations" if both the girl and the boy are of some age and educated (I suppose it was a Supreme Court Ruling). Now the problem is that the boy is in central jail in Bihar. And Police personnel (of the Rank of DySP) who are not deputed in the Central Jail are visiting the boy and forcefully making him sign on Blank pages.

The girl entirely denies that she ever sent any sms or whatsapp or calls to the boy which has the content where it shows that she consented to have physical relation with the boy. Also, recently, and off the record, she committed to a mutual friend that she will make sure to extract money from the boy and that she had it all planned.

What can be done in such a case. Also, can the SMS and Call Records (CDR) be sought by the service provider so as to bring justice to the boy.

Parents of my friend have already lodged a complain with the SC/ST Cell. But they too said that we need the SMS/WhatsApp/Call Records to go ahead and take action. And the police have taken the cell phone and have disposed it.

Please Suggest.