No,that's what DLD gained,that's the best case scenario.If DLD gained 2 inches it doesn't mean anyone could gain 2 inches.To gain 2 inches in 6 months is a huge thing and very unlikely,imo the only reason DLD gained so much is because he gain length easily and he was a beginner at the time.The average person will gain about 1" with the [words=http://www.mattersofsize.com/forum/penis-enlargement-newbie-forum/1597-dlds-first-routine-i-gained-2-inches-with-this-routine-full-tutorial.html]newbie routine[/words] in 6 months imo,and cement it of course.
Could be possible to gain 2 inches in 6 months but you have to be a length gainer

For me,i will need around 1.5 years to gain 2 inches.Depends if you gain length easily or not.