If it's the one which dangles down to the lower fairing as a drain, then I'm with thewiz and it should be connected to either the header tank overflow or the petrol tank overflow.
have breather tube that goes from tank to under bike but . Before it goes under the bike there is a T pice with second tube coming back up ?????? Can't find where it goes??????
There should be 2 pipes coming out of the hoop attached to the side stand bracket. Trace the end connected to the T-peice and see if it's for water or fuel. That should help figure out where it goes.