If the medicinal plant is already in use under under Ayurveda, Siddha, Unani systems and to take licence under Ayurveda, Siddha, Unani Drugs, pl go through the 'Guidelines for issue of licence with respect to Ayurveda, Siddha or Unani Drugs' (GSR 663 (E), dated 10-08-2010 of Drugs and Cosmetics ACT 1940, Rules 1945.
You may also refer Drugs and Cosmetics ACT 1940, Rules 1945 for further details.