If you are eligebale for change of status, does NVC send you a letter where they ask you whether you want to adjust your status or go through the

The NVC does not send any such letter asking whether you wish to adjust or consular process your case. To the NVC, your choice was made at the time that the I-130 petition was submitted when your petitioner filled out whether you were doing one or the other. You can of course change your mind during the process. If you are legally in the country at the time that your priority date is current, you may be able to file an adjustment of status application with U.S.C.I.S. instead of consular processing your immigration papers. However, kindly note that the priority date must be current before you can do this. It will take the same amount of time for the date to become current whether you are outside the US waiting for consular processing or in the US contemplating filing for adjustment of status. There is also no procedure that would allow you to file for adjustment of status ahead of the priority date becoming current and being allowed to stay in the US during the intervening years. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.  

You may only adjust status if you are in the US currently (legally) and a visa number is currently available.