I have this situation that I have 10 activities in my stream. But I don't want to deliver 5 activities since the code from the 5 activities already exist in the parent stream. If i lock and obsolete those 5 activities that I don't need to deliver, will it resolve my issue?
Maybe, if the activities are completely unrelated (no file in common, meaning the versions in the second activity don't depend on the versions of the first lock obsolete one)
The problem is if those activities were already delivered (the one you want to lock obsolete): a deliver creates a timeline which links all present activities on a stream (the one delivered and the one not yet deliver (see more here).
Another deliver would force all activities to be linked together in that new deliver.