1)Take the documents which u got from India alomg with the pasport to Indian Cultural Centre.
2)They will issue an NOC which need to submitted at immigration dept (Gharaffa)
3)They wil ask u to come back after 2 weeks after which u will issued an letter which need to be given to Gulf Times for publishing ad in newspaper.
4)At the sametime u need to put ad in Indian Newspaper(not Qatar edition)
5) after 2 weeks take both the ads and submit it to immigration
6)They will ask u to get 1 document typed which can be done near to immigration itslef. Should be in english
7)Once you get it typed get it stamped from Gate no 1 1st floor.
8)Take it to ICC along with the ads
9)They will give u the forms to apply for new passport wherein it will reflect ur family name.