I am a permanent resident, my fiance has entered the country on a B1 visa, can we get married and can she stay with me?

I suggest you consult with an experienced Immigration Attorney BEFORE you do anything. The money you will spend now may be well worth the investment should you act in a way that may be detrimental to a case later on.

Under current Regulations she will not have an immediately available immigrant visa since upon her marriage to you as an LPR she falls into the Family-Sponsored Preference Category of F2A (Spouses and Children and Unmarried Sons and Daughters of Permanent Residents) and the current priority date for visa availability for Indian Nationals as per the November 2012 Visa Bulletin is 15 July 2010. That indicates that there is an approximately 3 year wait for visa availability in the F2A Category at the present time (assuming she already had filed and received a "priority date". We recommend that you engage competent immigration counsel to help you once you have actually married her because the spousal adjustment of status process is both complicated and lengthy (over a year once filings have been properly submitted).

The key to this will be calculating when you will be eligible to apply for naturalization.

If you become a US citizen, then you can petition for your wife and she can apply for permanent residency at the same time, without returning to India first. If you only moved permanently to the US in 2011, the permanent residency you obtained in 1989 may be suspect. You should consult an immigration attorney.

There is an approximate 2 year wait for foreign national spouses from India who are sponsored by US Permanent resident spouses. She will need to go back to India and wait for her visa number to come up after you sponsor her. You should contact me or another immigration attorney of your choice to set up a phone consultation so you are aware of procedures and pit falls of marrying and filing immigrant paperwork for someone on a non-immigrant visa.