legal advice

one of my friend found that a bank authorities are indulged in frauds. He got some records of the bank with him which can prove the frauds. He has given that information to a TV channel which telecasted it. The bank officials not only did frauds in the bank but also helped some people to loot government funds also by issuing back date Drafts. He has written a complaint to the RBI and the RBI has verified such frauds in their regular Inspection and found that the frauds are true. It has mentiond the same in the Inspection report. The Inspection report is sent to my friend by some unknown people along with some other documents. Now the bank authorities planning to file a false criminal case on my friend with the bank funds with a statement that he is deframing the bank which effect the bank and give wrong view to the public. But infact if the public know the facts about the frauds they will proceed on the bank authorities. Now I want to know that whether my friend file a case in the police station with the documents that he received from unknown persons or he can file a case in the court as a PIL to safe guard the interest of the depositors of the bank. My friend is a share holder as well as a depositor in that bank. please clarify.