Can I install 16gb ram into mac mini mid 2011

Yes,

http://eshop.macsales.com/shop/memory/Apple_Mac_mini/DDR3_1333

Or Crucial.com

I'd opt for this:

Corsair Vengeance 16GB (2x8GB) DDR3 1600 MHz (PC3 12800) Laptop Memory

http://www.amazon.com/gp/product/B0076W9Q5A/ref=oh_details_o02_s00_i00

Works great.

Which model Mac Mini do you have rayhigh, becauce PC3-12800 1600MHz RAM is for a 2012 Mac Mini?

trungly88's 2011 Mac Mini takes PC3-10600 1333 MHz RAM.

see > Mac mini (Mid 2011): Memory specifications and upgrades

or > OWC's Memory Upgrades for the Mac Mini's

Sorry, I obviously cannot read. 😐 I have a 2012, that advice is good for 2012, not 2011. Sorry....

No problem, it happens to most all of us at least once or twice... 😉

These work great for me in my 2011 Mini Server

http://www.newegg.com/Product/Product.aspx?Item=N82E16820233251