Going from a non immigrant category to Permanent residency?

Question

What is the wait time to recive a visa number under category EB-3 (employment base)? and what happens to the alien while he waits for the change of status, can he/she stay in the country while the visa number becomes available ?

Answer 1

It depends on your current status. If you are H1B, you can change to an immigrant status while in the US, if you are J1 you cannot. BTW, you are a foreigner not an alien - just because Americans call you that, does not mean you have to.  

Answer 2

As of August Visa Bulletin, EB3 visa is unavailable. And it has been backlogged about 2-3 years unless your citizenship is China (5.5 years), India (7 years), Mexico (6 years).

http://travel.state.gov/visa/frvi/bullet...

Once the visa number becomes available, you can either file I-485 as Adjustment Of Status in US or I-485 Register to Permanent Resident through US Embassy in your country and go through Consular Processing.