You can download various Clash of Clans Private Severs or MOD APKs from here. Currently, only two private servers are here: Atrasis and Null’s Clash, both are working and support real-time battles. Also, both these servers provide regular updates. You can download for Android with these buttons:

Atrasis COC (444 MB)

Get Atrasis COC for Android v16.654.14 with TH17

Null’s Clash (254 MB)

Get Null’s Clash for Android v16.386.9