Please I need your advice on the type of business I can venture into with 270k that can make me to be self reliance because I am tired of working for bosses.
Initially I was thinking of venturing into transportation but what type car/vehicle can I acquire with 270k

Whatever you do, don't quit your job that helped you save that money. Start a business to supplement your job but don't quit that job.

Regarding your question i don't know but you can invest that money in treasury bills or mmf(the rates are very low now but there's security of capital). The truth is the more the risk, the more profit you make.
Good luck!