In the final round qualifiers, second seeded Tiwari beat Jatin Dahiya 7-5 7-6(4), while Pune-based Thakkar, seeded fourth, registered a 6-4 6-4 win over Lakshit Sood.
Chaukulkar, seeded fifth, outplayed Shahbaz Khan 6-2 6-2 to advance to the main draw.
Ting Yu Chuang, Hsueh Peng Chih, Hung Jui Chen -- all from Taipei -- William Kendall of USA and Sebastian Ofner of Austria were other qualifiers.
The results (final qualifying round): Hsueh Peng Chih (TPE) bt Aroon Khatter(Ind) 7-5 6-2; Abhijit Tiwari(Ind) bt Jatin Dahiya (Ind) 7-5 7-6(4); William Kendall (USA) bt Fariz Mohammed (Ind) 6-3 6-2; Rakshay Thakkar (Ind) bt Lakshit Sood (Ind) 6-4 6-4; Tejas Chaukulkar (Ind) bt Shahbaz Khan (Ind) 6-2, 6-2; Hung Jui Chen (TPE) bt Ronak Manuja (Ind) 6-4, 6-0; Ting Yu Chuang (TPE) bt Akash Wagh (Ind) 6-4 7-6(4); Sebastian Ofner (Aut) bt Vignesh Veerabadran (Ind) 6-4 6-4.
Following are seedings:
Singles: 1. Christopher Rungkat (Ina), 2. N Sriram Balaji (Ind), 3. Huang Liang-Chi (TPE), 4. Saketh Myneni (Ind), 5. Jeevan Nedunchezhiyan (Ind), 6. Ranjeet Virali-Murugesan (Ind), 7. Mate Pavic (Cro), 8. Nicolas Reissig (Aut).
Doubles: 1. Saketh Myneni / Purav Raja (Ind), 2. NSriram Balaji/Arun-Prakash Rajagopalan (Ind), 3. N Vijay Sundar Prashanth/Ranjeet Virali-Murugesan (Ind), 4. Mate Pavic (Cro)/Nicolas Reissig (Aut).