Hi! I would suggest you wait until you’re 18. It’s only just two years and you will get the chance to really think about the desing/placement.
If it’s something really dear to your heart, you will still want it in two years. I know you will, because it’s for your brother that you really miss, so take your time to think of the perfect tattoo that will remember you of him every single day.
I know that in some tattoo shops you can get tattooed at 16 with your parents agreement… but, personally, I got a tattoo at 16 and now I regret it and I want it covered. Almost everyone I know that got a tattoo between 16 and 19 regret those.
I’m not saying you will regret it, since it’s for your brother but maybe you want to think carefully about the desing, the placement, the tattoo artist, the size of the tattoo,…
A tattoo is on your skin forever, and it’s hurts like hell to get it remove, so just make sure that’s really what you want.
Hope I helped Xx