Modi started his first class career with a century on debut at the age of 17 in a Bombay Pentangular match.

In the wet summer 1946, when India toured England, Modi was somewhat a veteran in the domestic circuit, having made his debut five years earlier and was selected in the Indian team on the back of some impressive performances like scoring 1008 runs at an excellent average of 201 in the 1944–45 Ranji Trophy season, becoming the first ever player to do so, until W.V.

Modi had already earned a reputation for being a heavy run-maker, as his exploits with the bat made up for impressive watching: centuries in seven consecutive Ranji matches for Bombay in the seasons of 1943–44 and 1944–45, three double-centuries in 1944–45 (the same season when he amassed over a thousand runs), and a fourth the following year against the Australian Services team.

When the match started, India found themselves in dire straits as their scorecard read 44–3, when Modi walked in.

As recounted by Vijay Hazare in the book 'A long Innings', "Modi nonchalantly gave a thumbs up to the Indian dressing room (after the drop), and proceeded to play some delightful strokes".

In the West Indies tour of India in 1948–49, Modi performed excellently, scoring 560 in five Tests with a hundred and five fifties.

Described in John Arlott's words as being "...tall, painfully thin, grey of face and huddled into an overcoat, tending to tremble...", while noting the difference between the Modi on the field and off it.

He served as the ADC to the Bombay Governor Raja Maharaja Singh and later became a highly placed executive in the Associated Cement Company.