For RTI Application draft form you can visit CIC webcite or following link:
For Postal Order: You will have to visit post office for buying postal order of Rs. 10/-, alternatively you can make payment either by Demand Draft (DD) / Banker's Cheque (BC) or even by your personal cheque (if the CPIO is local).
Please check the http://cic.gov.in/citizen-service and the information with respect to RTI can be obtained from here.
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