Magikarp's evolution is Gyarados.
For this I recomend putting in Magikarps till they hit evolution level than let them level up and evlove
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.
mainly last evolution of fish Pokemon lvs usually depend on where you are. Probaly best spot to use is in the resort area because you can catch magikarps level 1-100 and there easy to level up.
You can catch them if you use your old rod in water.
In Pokemon platinum only, you can get magikarps in resort area using super rod. Levels are random from 1-100.
You do not need 6 Magikarps to beat the League... Who told you that!!??
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.
6 magikarps
There is no evolution of Girafarig in Pokemon.But if your talking about the pokedex then the next Pokemon is Hippopotas
Duskull is a Sinnoh pokemon as in pokemon platinum you get darkrai which is the evolution of duskull.
Luxio evolves into Luxray at level 30 in Pokemon Platinum. To date Luxio has not had different evolution conditions in other pokemon games.