I feel like everyone is terrified of gigas. There are many ways to tame a giga, some of the best ones are the ones explained by a YouTube channel that makes videos about how to do things in ark called Nooblets. I've tamed multiple gigas by myself and the easiest way to do it is with a quetz and a platform saddle. Another way, is o use a glider suit if it is allowed in the map. Since gigas are almost only found on or near mountains, it isn't hard to grapple to the top and continuously jump off and glide while shooting it. You don't really have to take care of it other than food and narcotics, other dinos will not attack it (this is also explained by Nooblets). When you manage to tame it, just keep it in a safe, enclosed area, ceiling and all, especially if you're in PvP, as they rage when shot with missiles or explosions. Other than that they are completely safe to have around other dinos. When riding it, stay away from jumping off of cliffs, no matter how small. Avoid them at all costs, as this will quickly fill it's rage meter. Be sure to pack enough supplies, and don't make it swim, a megalodon killed one of my high level gigas 10 minutes after being tamed and after I had crossed the map when I was almost at my base. Have fun!
P.S.: the level of the giga doesn't really matter much because it doesn't scale as well as other dinos do.