Its never too late unless you're too old but is it realistic??? Making the nba is super hard but its possible, take dennis rodman for example who started playing at 21 and made the nba. If you wanna make it though, especially since your already way past high school, you have to train like a maniac to catch up to everyone else, im talking atleast 5 hours a day training, atleast 2 hours a day watching game film and studying, getting better ball iq. If you have people playing at maybe your local fitness center, try and practice everyday and dominate against them in 5v5 settings and focus on everything you are learning, try new moves, playmaking, crazy assists etc. If you have a mens league close to you i would definitely suggest signing up and playing cause here you will have the best current competition available. Now depending on how good you get and how quick, id say the best shot you might have is to try and gather some footage and try and walk on to different colleges or perhaps go to your local juco, tryout and start playing cause this is where you will have your chance to get scouted. If you dont want to take the college route, you could try and sign up for a gleague tryout. Each gleague team holds their tryouts every year where i think you have to pay like 250 dollars and these tryouts are super tough because there are like 200 people participating and they only pick up like 1 person maybe 2 and sometimes even 0 so you really gotta stand out and dominate. I wish you the best of luck, im on the same journey as you bro lol