Sinha founded the Sonnet Cricket Club in 1969 after he failed to get selected in Delhi's junior team for the C. K. Nayudu Trophy.
With an initial batch of 20-odd trainees and minimum facilities, the club did not get affiliation with the Delhi & District Cricket Association (DDCA).
The club was shifted to Ajmal Khan Park in Karol Bagh in order to allow cricketers from other parts of the city to be trained.
"[9] In early 2000s, the club moved to Sri Venkateswara College in Delhi University's South Campus, which remains its base as recently as 2020.
[1] In 2001–02, he was appointed head coach of the national women's team, when Mithali Raj and Jhulan Goswami were in their debut international seasons.
After his ouster from the RCA, he was appointed the coach of another Plate Division team, Jharkhand, whom he guided to the Ranji knockouts for the first time in the 2012–13 season.
At one point, when he was served an eviction note from his landlord, cricketer Ashish Nehra stepped in and bought him an apartment in New Delhi.