Which are correct and do the correct ones mean the same:

1-I am opening the door so he can come in.
2-I am opening the door so he will come in.
3-I am opening the door so he may come in.

4-I am opening the door so he could come in.

5-I am opening the door so he would come in.
6-I am opening the door so he might come in.


I am pretty sure the first one works.
'4' seems to introduce a condition.
'3' seems to suggest that I want to create the possibility of his coming in.
'6' seems to say the same thing, but it seems less possible that he will come in.
'2' and '5' seem to say that I want to create in him the willingness to come in.


Gratefully,
Navi.