You can only catch him once.
You can't catch groudon in sapphire only in ruby. To get him in sapphire you have to trade him from ruby to sapphire.
If you don't include trades, I think you are able to catch these. Ho-Oh, Lugia, Suicune, Entei, Raikou, Mewtwo and Latias. I have heard that you can catch Groudon/Kyogre (Only one of them, the other one is available on Soul Silver) and Rayquaza, but that I'm not sure of.
as many as you can catch.
Only once.
2 heart gold- kyogre and rayquaza soul silver- groudon and rayquaza
well i caught him on my first try so i believe just 1 time, hes not 2 hard 2 catch dw (:
weaken it, make it sleep and use many ultra balls it will work eventually.
It isn't a matter of how many times you defeat it; your level and rank need to be high enough.
5 times
over 9000
You can catch Suicune at many points in the game. It depends on when you caught it. It is impossible to say what you must do next.
there are three that you can CATCH in pokemon emerald its Groudon, Kyogre, and rayquaza regice registeal regirock litos lotias