Boot screen freezes after updating RHEL 6.2 to RHEL 6.6

Yesterday in my lab I got a new system which was actually a old system and we were running it since last 5 year without any issue.
but when I got this I found that there was not even a single software was installing for e.g. teamviewer
so I downloaded rpm from official site and than tried to install it using "yum install teamviewer_version.rpm" command in terminal
but it stopped for dependency after several time of trying. so I searched for problem by googling it and get to know that dependency automatically able to download only when you have a active subscription of RHEL
so I searched for CD in my lab and got a 16 digit key xxxx-xxxx-xxxx-xxxx like this
than I activated subscription and got approx 712 update for my system I installed them and later on run command "yum install createrepo" than succefully installed software like teamviewer chrome etc.
but problem started when I restarted this system
after restarting it stopped a screen whicj having a bar in bottom of screen and also name of version of linux which says "REDHAT ENTERPRISE LINUX EDITION 6.6"
I waited for 15 minute but nothing happens so I restarted it again and this time I selected boot option with old version which was RHEL6.2 but again it stopped at same screen
so I again searched on google for this problem and figured it out that it is because when you update kernel than there are some phenomena called "SELinux" relables all file I can figure it on that very screen where it is stopping by press 'esc' so I did it for RHEL 6.2 so I found out it some thing like
"
*** Warning -- SELinux targeted policy relabel is required.
*** Relabeling could take a very long time, depending on file
*** system size and speed of hard drives.

"
where * says 1000 file labeled
I left it for labeling after 2 hour again that boot screen appeared and again it is same condition that bar and RHEL6.6 tag
so question is if I booted it for RHEL 6.2 and also labeling it for 6.2 than why RHEL6.6 appeared after completion of that labeling and why it is stopped again on that very screen
this time I am not able to press 'escape'

system size is 8TB and it is raid configured