Thanks for replying. I am completely in accord with this process. Actually, wanted to know, after 3 or 4 years down the line, when I will apply for my biological parents's visa, then I will face this issue of not having their name on my documents. So, What could be done now, shall I disclose this whole scenario to IRCC right away. Thanks.
I do not fully understand your question. Are you asking if you should put your real parents information in your PR application? If that's the question, then YES. Put your real parents information there unless you have been legally adopted by someone else.
If your parents are not married to each other any more, when you apply to sponsor them for PR, they will be under 2 different applications which will cover their new family as well. (just in case)
If my guess is wrong, and you are asking about sponsoring your grandparents, you should also put in your actual parents information. There is option to sponsor grandparents. And as long as you have the proof that your grandparents are parents of one of your parent (birth cerificates), then this should not be any issue in the future.
Basic rule of thumb is put the fact/truth on the application. Do not leave anything out that could affect you in the future.