You can catch them if you use your old rod in water.
Magikarp's evolution is Gyarados.
route 222 (good rod) mainly magikarps
Get a super rod in Pokemon Platinum and then fly to resort area. Fish in the water and Magikarps will come up. The Magikarps are lvls 50-100.
If you mean the magikarps in the resort area, then take a super rod and fish there. You will find many Magikarps, ranging from lvl 40 to lvl 100. which is the "creature that lurks in the resort area." hope this helps. You can get to the Resort area after you beat the Elite Four. Get a super rod in the fight Area in the top left.
catch two magikarps, male and female, train them to level 30 each, both of them MUST be at level 30. however DO NOT let them evolve right away. keep them as magikarps, make them have an egg, then the you will have a red/shiny garydos.
In Pokemon platinum only, you can get magikarps in resort area using super rod. Levels are random from 1-100.
nothing because you find magikarps always in water.
For this I recomend putting in Magikarps till they hit evolution level than let them level up and evlove
You do not need 6 Magikarps to beat the League... Who told you that!!??
5 million
dont throw a pokeball at it!
6 magikarps