Beat the 8 gyms.
at indigo plateu
In the indigo platue
...There is no Pokemon game titled "Pokemon Indigo". Assuming you meant "After you beat the Elite 4 at the Indigo Plateau", you do not 'receive' any Pokemon per se, but you do unlock the national dex allowing you to get Pokemon past # 151
you have too have all the Johto badges first then go to the Elite 4 and there is one type of legendary Pokemon on each Elite 4 map
at the indigo platue past the victory road
The Indigo Plateau.
You will need beat the elite four in Pokemon Indigo in order to obtain Deoxys. After beating the elite four Deoxys will randomly spawn.
You have to go to the Elite 4 to get an eevee.Trust me. it took me 3 years to figure out that you can only get them in the Elite 4, because my brother found 18 in the Elite 4, but nowhere else.
You have to first earn all the gym badges, and then you have to enter the elite 4
at Indigo Plateau
They are at indigo plateau
At indigo plateau