Threatening for Pre wedding dowry case

Hello, My brother got engaged in Dec 2020, after the engaged my brother came to know that girls are not interested in taking with him. Always saying that no need to talk with me and blocked his no. So my brother is also worried. He gave girls no to his younger cousin brother or sister to talked with girls so that we came to know what's the problem. But girl blocked that number also. After searching he came to know that girl was envolved in kidnaping case in 2017 and had punishment of 8 month in prisones and that case is still oper. But now girls family is threatened us to file false dowry case against my family. Is it possible to file fake dowry case before marriage if boy denies from marriage because girl is not behavieng like she is interested in marriage at all. Pls suggest me what to do as I am a middle class person and can not afford lawyer and police expences. As girls family is demanding 1 lakh rs for not marriying or otherwise marry with girl and give them written confirmation on paper that nothing harm should be happen in future to girl. Pls suggest girls family filed ncr in police station on 7 may after marriage date and I also filed my ncr report against girls family on 12 Apr before marriage date. Waiting for your reply