The Indian duo was 12 shots behind the leader, the 14-year-old Guan Tianlang of China.
The best Indian performance was by Joshi, who played a three-under 69 with six birdies and three bogeys. Chikka's had rounds of 69, 74 and 71.
While Joshi had the day's best round among the Indians with a 69, Udayan Mane (75-75-70) was the next best with a 70 and he moved up to tied 27th at 220.
Angad Cheema (77-72-72) was lying tied 32nd at five-over, Honey Baisoya (76-72-76) was tied 38th and Manav Das stayed at tied 43 with a rounds of 79, 70 and 75 for a total of nine-over 225.
Tianlang continued to lead the field even after carding a third round even-par 72. He held a two-shot lead over Australian Oliver Goss going into the final day.
After leading on the first two days with rounds of 66 and 64, Guan remained at 14-under, but the big-hitting Goss, a quarter-finalist at this year's US Amateur, closed in on his playing partner with a bogey-free 69 at Amata Spring Country Club in Chonburi.
Thailand's Prin Simmisomai (70-65-72) at nine-under 207 is third, Korean So Min Lee (69-70-69) at eight-under 208 is fourth and Chinese Taipei's Cheng Tsung Pan (75-67-67) at seven-under 209 is fifth.
The winner earns an invitation to next year's Masters Tournament, while the champion and runner(s)-up earn spots in International Final Qualifying (IFQ) for The Open Championship.
