Gotra Soni is not a gotra. It is a name for a profession, it is found in many Gotras.
There was an oswal soni by name Sangramsingh, a poplar fallow in the times of Sultan Allaauddin Khiljee his decendent was soni sangramsingh. His father was Nardeva who had been the Treasurar (Bhandari) of the king Husang. Sangramsingh was a warrior brave polite and a learned person. Emperor Gayasuddin Khiljee honoured him with the title of ‘Nagdul Nuluk’. He donated 36 thousand gold coins, by means of which many Gyan-Bhandars (Libraries) were opened. His book ‘Budhi Sagar’ written in Sanskrit Poetry contains the description of Deva (God), Teacher, Religion, Astrology, Vadhyak. Vastu Kala, Shakun, Ratna, Coins, Palmistry, etc. It was completed in pratisthanpur in V. 1520. Its comment Book ‘Sangram Soni ras’ is very famous.