My mother surrendered her green card last year in our native country and got herself 10 yrs visitor visa now she is here on visitor visa and has been issued 6 months visa on arrival at the airport, I am a usa citizen and would like to apply for mothers green card again, which form do I fill up? How long does it takes usually to get approval?
Is it easy now while she is here to apply again ,will it be treated as new green card?

Please note that if she entered with a visitor visa, and intended to immigrate, the USCIS officer can make a determination of visa fraud, deny the permanent residence and start deportation proceedings.

To answer your question specifically, you file the form I-130 relative petition and your mother files the I-485 application for adjustment of status. There are several secondary forms, the G-325 biographic forms, the I-864 affidavit of support as well as the forms for the EAD and AP.

It will be treated as a new application, so it is fairly easy, but you will need to explain why she relinquished her green card and the details of her most recent B visa application and intent on entry.

Consult with an experienced immigration attorney. Good luck.