The Reserve Bank of India introduced the INR 200 denomination notes on Aug 25, 2017. Introduction of this denomination is expected to facilitate exchange transactions for the common man and provide complete series of denomination for transactions at the lower end.
These notes are available only through select RBI offices and banks as is normal when a new denomination of notes is introduced and the supply increases gradually. However, the production of these notes is being ramped up by the currency printing presses, and over time as more notes are printed, it will be distributed across the country through the banking channels and will be available for public in adequate quantity. (Source)