Hey Musharna to get shinx you need to turn the PokéGear Radio onto the Pokémon March station on a Thursday and you will start to hear the song of the Sinnoh versions and while the pokegear is playing it you have to walk for the routes 29, 33, 36, 37, 38, 39, 46, 48 and the National Park in Johto or in Kanto for the routes 2,3,5,7,8,11,14,15,16,17,18. But to get the sinnoh sound obviusly you need to beat the Pokemon League first.
Hey guys i will like to know how to get cyndaquil in my Heartgold game cause my first pokemon was Totodile and later i get Chikorita through GTS trade but i can't seek Cyndaquil because i don't even see it, so if anyone could help me with this.