Charlie Oppenheim recently released a new update on possible movement of various visa categories. While for the most part there are no surprises, it is good to review what he says on your particular category to ensure you are not surprised in future months. However, overall, it was a short update this month.
EB-1: All countries should remain current for the foreseeable future (including China and India)
EB-2: Worldwide should remain current for the foreseeable future. India and China will have some forward movement but not much.
EB-3: Worldwide should remain current for the foreseeable future. India will most likely hold steady and China will move forward slowly. Charlie has been paying close attention to China especially because of the number of EB-2 downgrades. To prevent any retrogression, Charlie is only moving forward slowly in that category. The Philippines should also progress slowly.
Family based: Mostly modest movement forward. The only surprise is FB-4 for India, which is having lower than expected demand and may move forward more quickly than Charlie previously thought.
Immigration Briefs 
For your attention (Family based: Mostly modest movement forward. The only surprise is FB-4 for India, which is having lower than expected demand and may move forward more quickly than Charlie previously though)
NB:-please check and change EB-4 instead of FB-4.
Actually it is the FB-4 (Family Based 4th Preference: Siblings of US Citizens) category that I am talking about.
My pd is 12 March 2011 and my category if f3,when is my pd becoming current as I got a mail that my Visa number has become available in 2016 March.
Without knowing more about your case I cannot really tell you when it will be current. What I can tell you is that right now, F3 is at November 8, 2007 for most of the world (and in 1996 for Mexico and 1998 for the Philippines), so there is still quite a wait for you. I am not sure wh you received an email in 2016 about your priority date being current considering that F3 appeared to be in 2004 at that time.
My pd date is 15 august 2005 F4 catagory can u tell me estimate time for wlcome letter
Are you in the US? Did you file the I-485 already? Or are you from India? If you are from India, there could still be a year or more that you need to wait for them to get to your date.