Hello i ve done the jirachi quest then after catching jirachi i started the evolution data for catch latios. After some days i ve finished the evo and tryed to catch latios but once i talk to the tv it says a blue pokemon is roaming around. i ve also tryied to defeat again latios but i can t find it in none of the spot.

Hi there @ReborniKing

 

My apologies for the inconvenience. It looks like you've simply not encountered the Latios yet, which is required for the quest. Could you check the following locations and screenshot them if possible ? I have listed them below with screenshots of where you will possibly find Latios. You may also find those in the legendary megathread. 

 

Petalburg maze - Follow the white line

Devon Corporation 3F 

Granite Cave 1F2

Route 124 Underwater - Second picture

Route 123

Shoal Cave (low tide ice room)

Mossdeep Gym

Sky Pillar 5F

Victory Hoenn road (cave)

Route 134

 

Looking forward to your answer, have a splendid day!