no it is not possible
It is only possible by cheating.Not by regular gameplay.
Sorry but you have to catch Regice, Registeel and Regirock in order to catch Regigigas.
You Can't
Regigigas requires all 3 of the other Regis to be present in order to be captured.
get it asleep or paralyse it. then use a ultra ball
You can get regigigas by either trading it from the event before the release of platinum, or migrate the regis from ruby/sapphire/emerald, then go to the cave in snowpoint city, and catch it while you have all 3 of the regis in your party.
You are not able to catch the regis in Diamond. You can catch them in the Game Boy Advance version of Pokemon Emerald.
Yes, if you have the three Regis, you can go to Snowpoint Temple and catch it at level 70 in Diamond and Pearl and level 1 in Platinum.
nothing. you catch them. what more can you ask then the regis'? don't be selfish! and you cant catch regigigas.
unfortunately you can't without regis
no.