If any one came to Doha, 3 months will get as probation period to finish all the requirements to make ID. In that period, if the company terminate employee with out any reason,he can give the complaint against the company. if you get the job and they give N O C to change the sponsorship, they have no right to take action against you. And you must do medical again and finger printing too.The P R O of that company will clear your finger from that department in 10 minutes. Any how, Best of luck....