Use RMAN if endians are same which will not be the case mostly.
If endians are different:
Export/import process for R12 using 11gR1 or 11gR2 [ID 741818.1]
Using Transportable Tablespaces for EBS Release 12 Using Database 11gR2 [ID 1311487.1
I will detail the option -1 in the coming days.