This is prerooted zips based on C6602 Customized US 10.6.A.0.454 and C6603 10.6.A.0.454 Customized HK, downloaded with Xperifirm, packacked by flastool and rooted with PRFCreator. I myself tested it on my C6602 and root worked (with SuperSU). Haven't tested C6603, but it should also work. I don't take responsibility for any damage to your phone.
Download (C6602): Mega
Download (C6602): Google Drive
C6603 rom seems not to be flashing, so I removed it for time being.
As users have been reporting, flashing with twrp results in fail, so flashing with CWM(or recovery based on it) is advised. Also you should be on stock 4.4.4 (rooted with recovery) before flashing.