I was trying to connect to a game I was in when it disconnected me and I was able to connect once it was 3 minutes in the game. Even though I was connected my team still remaked the game and 3 of us said no and I got 20 minute leaver buster for it.
/remake becomes active when a player is disconnected for at least 90 seconds of the first 3 minutes. Even if that player reconnects after 90 seconds his team will still have the option to remake due to the disadvantage they were put at. /remake also becomes invalid if there was first blood on the player's team before he disconnected.
https://support.riotgames.com/hc/en-us/articles/208754686--Remake-FAQ
