Evidence

In reality the courts dont seem to pay much attention to source of doucments. The approach taken is that admit the document, if the evidence is inadmissible it should come out during cross examination and its admissibility will be taken into account later. Also in your particular case the defendant will state document was obtained thru RTI and if the officer provided information, if there is any act of illegality it was done by the RTI officer and not the defendant. In the end the PO will ask you if the document was infact exectued by the plainitiff and if so why the plaintiff did not produce it or if there was an act to supress this inforamation before the court.

The court will go by the genuineness of the dcument relied upon by the party presenting it before the court and will not go beyond the source from which it was obtained.  There are settled laws in this regard by supreme court judgements.