Answer 1

To make tyranitar learn stealth rock you should breed it with a male pokemon knowing stealth rock.
Definitively there's no pokemon which can learn this move via level-up AND breed with Tyranitar, so the only way to get it is to transfer from D/P/Pt/HG/SS a pokemon knowing stealth rock and which is in the same egg group of Tyranitar and breed it with. Or simplier, transfer a Tyranitar from gen.IV already knowing stealth rock.

For Hippodown the only way is to transfer it already with stealth rock from Gen.IV because it can't learn it via breeding.

Comments

so,only transfer will work??=((,,bad
but thank you,i already know that there's no way beside transfer,,,big tq bro to clearing thing =))

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Pokemon that can breed with a female tyranitar and know learn the gen four tm:
male Nidoking, cubone/marowak, rhydon/ryhorn/rhyperior, marshtomp/swampert, aron/larion/aggron, turtwig/grottle/torterra, craindos/rampardos, sheildon/bastiodon, and gibble/gabite/garchomp