Patel too has recovered from a rib injury to join the 15-member squad as a potent death-overs bowling option alongside veteran Bhuvneshwar Kumar.
Of the two wicketkeepers in the Rohit Sharma-led squad, Rishabh Pant gives India the option of playing the left-handed batsman as a free-moving ‘floater’, while Dinesh Karthik has a formidable reputation as a ‘finisher’.
India, who begin their campaign with an 23 October blockbuster against arch-rivals Pakistan in Melbourne, will miss the injured Ravindra Jadeja but have a like-for-like replacement in spin all-rounder Axar Patel.
Seasoned Ravichandran Ashwin was picked as the second spinner, behind Yuzvendra Chahal.
The seam duo of Mohammed Shami and Deepak Chahar, middle order batter Shreyas Iyer and leg-spinner Ravi Bishnoi have been kept on standby.
India, who could not make the final of the Asia Cup in the United Arab Emirates, will host a three-match T20I series against world champions Australia from 20 September.
It will be followed by six limited-overs internationals against South Africa at home before they fly to Australia.
India T20 World Cup squad: Rohit Sharma (c), KL Rahul, Virat Kohli, Suryakumar Yadav, Deepak Hooda, Rishabh Pant, Dinesh Karthik, Hardik Pandya, Ravichandran Ashwin, Yuzvendra Chahal, Axar Patel, Jasprit Bumrah, Bhuvneshwar Kumar, Harshal Patel, Arshdeep Singh.
Standby: Mohammed Shami, Shreyas Iyer, Ravi Bishnoi, Deepak Chahar.