Hi and welcome to the best ‘male enhancement forum’ there is. Yes, you can most definitely gain just as we all can. You’re at very decent starting size so reaching 8x6 should not be much of a problem. Go check out the ‘newbie routine’ as there really isn’t any better place to start than right there.
Follow it for 3 months, keep consistent and if you’re gaining from it just keep on doing it, just add more reps or time. No need to fix or try to improve on something that’s already working.
I’m still to this day gaining doing the ‘bread and butter’ that is basic stretches and jelqing which is the main focus of the ‘newbie routine’ as well. Good luck gaining and remember it’s not sprint but a marathon as gaining takes some time.
If you’re lucky you’ll as many others on here get some easy newbie gains and reach 8x6 in no time. You’ll most likely reach the length goal first as gaining girth is the harder part for the majority of gainers.
Start with this; Newbie Penis Enlargement Routine
“There he goes. One of God's own prototypes. A high-powered mutant of some kind never even considered for mass production. Too weird to live, and too rare to die.”-Hunter.S.Thompson-
As long as a big can of Gillette shaving cream(7,5" or 19 cm), with picture proof in the 'full body picture' section. Pictures is the ultimate proof in the pudding, IMO.