From what HRCT has said, we know that they are not "merging" with the subs. If HRCT were to merge with the parent, one of two things would happen.
1. ZDSoft could buy out the remaining shares of HRCT. But this is not likely this case since there would have been no reason to sell the subs to HRCT. This could still be a possibility if it was just a maneuver to gain control.
2. ZDSoft could merge with HRCT to get the public listing and essentially absorb HRCT. This doesn't appear to be the case either from what they have said. Again, there would have been no point in selling the subs to HRCT.