You can take two course of action- First in your case in the Court against Public Authority, file an application for production of original document. Second, you can file a complaint to the Information Commission about the incorrect and false information supplied to you. The Information Commission has the power to penalise the Public Information Officer and can also grant you compensation for detriment suffered by you on account of supply of incorrect and false information by Public Authority.
On the case pending in Court, the information supplied under the Right to Information Act is admissible as secondary evidence (under Evidence Act) and unless proved contrary, it is assumed to be correct. In case the Public Authority is disputing the correctness of the information, the Public Authority is required to produce original documents, which is primary evidence. If public authority is admitting that the information supplied to you is an error by its clerk, the onus is on the Public Authority to produce correct information. In such a case, you may file a compliant as well.