Is It True that People Like Magnus can see like 15 moves Ahed?

Well, I checked his/ her profile. I dont get error and I can see all his/ her posts.

Looks like @IPunishDaddy2007 is unmuted now, lol.

No, he's still chatbanned. Actually click on the link to one of his posts from today. I tried it both logged in and not logged in, and it gave me the 404.

grandmasters can do 10 moves analyse except magnus

Much weaker players can calculate fifteen moves ahead - not that hard. What's hard is to determine which sequence of those fifteen moves is the best. I honestly hope the OP is a troll.

YES AMMAR2012 but Magnus can do it too.

Do they calculate to depth 15 like computers do? No, they can't use brute force calculation and it's not necessary. What they do is pick up the most interesting lines using their positional and tactical knowledge and start calculating from there. And they can do more than 15 moves for sure.
Do they calculate 15 moves in blitz? No, it's very unlikely.