The RBI has said it had processed 9,711.62mn demonetized Rs. 500 notes and 4,709.72mn Rs. 1,000 notes till August.
However, it claimed to have no information on fake currency as "processing is in progress".
It also refused to give details of printing defects in the new notes citing "economic interest".
Rs. 15.28tn worth of old notes had been deposited in banks till June.
After demonetization, 4,292.225mn new notes of Rs. 500 and 3,542.991mn of Rs. 2,000 were printed till March, an RTI reply revealed.
However, there have been several complaints of variations in design and color. RBI had assured they are valid legal tender.
"Steps have been initiated to acquire more Currency Verification and Processing Systems (CVPS) machines on lease," the reply said.
Meanwhile, the DRI has nabbed six persons, including a Congress office bearer, and seized Rs. 24L in a fake currency racket.
A Nashik mint reported the counterfeiters in Bangladesh had successfully copied at least 15 of the 30 security features in the new notes, including "embossing of Mahatma Gandhi and water color marks".
Security threads were also replicated.
This comes less than two months after Finance Minister Arun Jaitley claimed demonetization had helped rout out fake currency from the system.
At the same time, the government accepted it had detected Rs. 11.23cr in fake currency since November'16 to July'17.
The RBI has developed an app for Android and iOS to help users check the authenticity of notes.
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