If you are a noob at modding don't even bother with rooting. Its dangerous and BTW I think your firmware has KNOX which the GMega doesn't have a workaround.

Sent from my GT-I9200 using Tapatalk
Galaxy Mega 6.3 GT-i9200 - Stock
Asus MeMo Pad HD7 16gb - Stock & Rooted
OnePlus One 64GB Sandstone Black - Stock

Galaxy S2 GT-i9100T - SOLD
iPhone 4 32gb - SOLD
Nokia Lumia 610 - RETIRED
Blackberry 9810 - RETRIED
Nokia E63 - RETIRED

Nexus 7 2012 32gb WiFi- PSX ROM - DEAD