aremla,
If your here in UK on work permit you can apply your ILR on Form Set(O)
You must have lived in UK for a qualifying period of 5 years as a work permit holder.
(note that if you first came here under the Highly Skilled Migrant Programme (HSMP) before 3 April 2006 you can apply after living in UK 4)
You can apply for ILR 28 days before completion of your qualifying period.
Look here:-
http://www.ukba.homeoffice.gov.uk/se...ionformset(o)/
Fee if applying by post:-
Main Applicant £900.
Each Dependant £250.
Fee if applying in person at PEO:-
Main Applicant £1250.
Each Dependant £350.
The guidance notes are here:-
http://www.ukba.homeoffice.gov.uk/si...dseto04091.pdf
You can download the form here(look at the bottom of the page):-
http://apply.ukba.homeoffice.gov.uk/...EAR_STATE=true