I don't know the limit but it's a different topic.But you can do something about this.
For example the limit of step in odi 10g is 7 but you want to make 12 step in a package.
So create a package for these 7 steps and generate package.Let's say this is PACK_1_to_7.
Then create an another package.PACK_8_to_12
In PACK_8_to_12, use PACK_1_to_7 as first step.Then take your other steps in this package and generate package.
I think this will solve your problem.