I want to update my iphone 4 to ios 6.1.2?

Hello so guys i have an iphone 4 currently ios 5.1.1 and i wanna know if i could update my ios to 6.1.2 even though itunes has 6.1.3 version? I also have 6.1.2 firmware i wanna if it is possible to do

Not possible, apple stopped signing for 6.1.2

No, unfortunately this is not possible as Apple has stopped signing 6.1.2. Sorry!