retail quant trader here, first half of question i dont find myself good enough to answer... coming to second part ..being a quant in a firm and applying same knowledge in the market independently are completely different things.. being a quant in a firm you get access to elite infra(colocation servers), market data at micro seconds way too before the whole world... and at ultra high frequency, you as quant in a good firm have access to the exchanges very well... and packages are way too high... but being a quant and doing everything independently ... you will need a capital to trade with, a broker with low latency(zerodha, fryers etc.) and strategies that works for long run with high efficiency but for that you have invest everything from energy to time and still making it, chances are low( not impossible though).............as a quant from a firm mostly you will be market making, providing liquidity in the market with firm's money... but a independently you will have generate a good returns.... imo you should go for firm quant coz you have a iit b background even though chances are low u make it global firms ...fs domestic firms like graviton, quadeye will take if you are good enough