It wouldn't be a 6/6 either way. It's either a 0/0 plus however many counters earthbending put on it (this is the case when the March was put on the field before earthbending the land), or it will be a 6/6 plus however many counters earthbending put on the land (this is the case when the March comes down after earthbending the land). 6/6 is not going to happen without further shenanigans.
Rezzahan#77802
It wouldn't be a 6/6 either way. It's either a 0/0 plus however many counters earthbending put on it (this is the case when the March was put on the field before earthbending the land), or it will be a 6/6 plus however many counters earthbending put on the land (this is the case when the March comes down after earthbending the land). 6/6 is not going to happen without further shenanigans.