777huhu, yes it is possible and their is plenty of time to make it happen. Contact your nearest recruiting centre and ask that your application be changed to ROTP.
If you have yet to do your aptitude test (CFAT), I recommend you devote some time to studying, it will have significant weight when it comes to selections. Check out the new practice CFAT on the Forces.ca website, it is found in the section labelled "How to join".
Thank you for your information.
I actually passed my aptitude test and Maritime Officer Selection Test(MOST). Now I have a medical test and interview left. I will contact to recruiting center to transfer to ROTP from RESO program as soon as possible.