Flag 0111 means in data part you have to stuff a 0 after every occurence of 11. So given data part is 011111 So after bit stuffing it will be 01101101
If flag contain consecutively n one then in data part you havr to stuff a 0 after every (n-1) one
Actually I asked this question for altogether different reason. If we stuff 0 after every 011 (flag is 0111) then the data will be 0110111 . Here after stuffing 0, at the end we have 0111 which is same as flag and the problem is not solved.
http://web.mit.edu/modiano/www/6.263/lec2.pdf
I have seen previous year gate paper in that they use to stuff 0 bit after every n-1 occurrences of 1.