The manager mode in FIFA 2017 hack is where the player will have to choose a club from the many options that will come under his control. With this the player will be assigned with the responsibilities of player transfers, looking after the entire play, overall game management and the like.
In FIFA you need to buy players, upgrade them, create leagues, or join some, upgrade leagues etc. But to do any sort of a upgrade or new purchase in FIFA you need coins. You can term coins as currency of FIFA 2017. There are many tasks that can be done within the game to collect coins. But they are less in number. Since coins is so important to FIFA majority of the FIFA hacks are related to unlocking unlimited FIFA mobile coins. Such hacks are most of the times coin generators which only require your login credentials to provide you with the required coin amount.