Letrozole and HGH if you want full maximization. Walk alot. Be active alot. Drink milk and get your calcium and protein. Sleep well. Based off of your brother, he grew late so you can definitely have a possibility that your plates are still wide open.
Letrozole can give you small headaches for the first month and small bone pain throughout if you run but if you can push through that then it should be fine.
If you can get generic HGH it's just heavy water retention especially on the face and with really long term use it's elevated blood sugar level that you can avoid with keto and less carbs and completely reversible after you get off HGH. Diabetes is unlikely, but if you eat literally all carbs like bowls and bowls of rice and do that right after dosing, it can happen across the span of months
I don't recommend either, because I don't recommend anything unless you're suffering but these are some ways to gain height