Lending policy is such a vast subject, and lending policy of any commercial bank is strictly within frame work and directives of RBI.
First go to website of RTI, get print outs of their policy directives and you can seek such information from CPIO of any Bank.
You can file RTI Application on any subject, there is no bar / limitations or exemptions for citizens.
It costs Rs.10/- as RTI fee and Rs.17/- registered post.
Public information officer has to either provide the information or deny information stating such exemptions with justification within 30 days of receipt of RTI.
So at the time of filing RTI applications, a citizen need not have any doubts. If information is denied, one can go for appeal to First Appellate Authority, a senior to PIO and then to Central information Commission.