Loan via neft

A and B are relatives. A gave loan via NEFT to B on October 2016. Amount is Rs. 5 lakh. No loan agreement was made. B is not paying back the amount. A filed complaint in police u/s 420 ipc. B plans to bring some cash bills for that amount claiming she incurred that on A's behalf. Whereas, A is ready for that nonsense by B, by being ready to say that she is tax paying citizen and she gave money to B to incur such expense and has Income tax returns each having income above Rs. 5 lakh ready with her. Who will win? Will A be successful in registering FIR against B?