와게 is incorrect word, which should be corrected into 오게.
But, '거기 오게 될걸' is also a bit wrong expression, which should be rewritten as '거기 가게 될걸' or '여기 오게 될걸'.
'여기 오게 될걸' means you are most likely to come here.
'거기 가게 될걸' means you are most likely to go there.
If you have a further question, please let me know. :)