This is how you get a Heracross with Rock Blast and Focus Punch in Pokémon X and Y.
First of all to get Rock Blast you'll need to breed a Female Heracross with a Male Dwebble, Crustle, Shuckle or another Heracross that knows Rock Blast. The easiest way is with a Dwebble, Dwebble can be found in Route 8, Route 12, Cyllage City, Ambrette Town, Glittering Cave and Azure Bay (Rock Smashing) in Pokémon X and Y. You need to make sure the Dwebble you catch is Male. Dwebble learns Rock Blast at level 5 so to get a Dwebble with Rock Blast you will have to take it to the Move Reminder located in Dendemille Town. She will re-teach Dwebble Rock Blast in exchange for a Heart Scale.
Now that you have a Male Dwebble with Rock Blast put it in the Day Care Center with a Female Heracross. When they eventually breed and the egg you receive hatches into a baby Heracross it will know Rock Blast. Make sure the baby Heracross is a Female because your going to have to breed again to get Focus Punch.
To get Focus Punch you need to breed your Female Heracross (the one with Rock Blast) with either a Male Pinsir, Ledyba, Ledian, Heracross or Volbeat that has learnt it in a previous generation.
When they eventually breed and the egg hatches into a Heracross it should know both Rock Blast and Focus Punch.
Hope I helped :)