Raghu, who had opened with an 85, finished with 162 while favourites Gurkirat Singh and Sunit Chowrasia finished second and fourth with totals of 163 and 165 respectively.
Overnight joint-leaders Raj Ali and Viraj Khanna ended up third and fifth respectively at the Royal Calcutta Golf Club.
Gurkirat, however, annexed the title in Category B with a two-round total of 163 while Raj Ali was second at 164.
Bishwam Ghosh was third at 176, while Udayjit was fourth at 177.
It was Bibek Sardar who won the Category C honours with a 36-hole total of 170 while Hashan Rahman finished second at 172 along with Devansh Chadha.
Sandeep Yadav emerged champion in the D Category with a total of 170 while Rajib Ali came second at 185. Aryaman Chakravarty won the Category E title with a total of 113 while Khushboo Sinha was the winner in the girls category.