@jignesh72
Let me start of by saying that some here on this forum will find my opinion controversial. Most of the members here on the forum have far, far more experience than me. The opinion I offer is exactly that, it is an opinion. It is not based on any professional knowledge or experience, it is simply my opinion based on my view of things. And as I said, the other members of this forum have way more experience than me, so I would take that fact into consideration when deciding which option to use.
As to your question on land border vs PRTD.
Firstly, applying for a PRTD should work. But the land border should work too.
When determining which option to use, as yourself these questions:
1: Do you have your original record of landing?
2: Do you have a SIN number?
3: Are you willing to stay in Canada for 2 years without being able to leave even once?
If you answered yes to all the questions, then you can consider the land border option. If the answer to one of the above questions was no, then unfortunately applying for a PRTD is the only feasible option.
Here is my view on which option is better.
Approval Rates: PRTD vs Land Border.
A PRTD has a high chance of approval. High is different to guaranteed. There have been cases where people in your situation have had their travel document denied. It is rare, but it does happen.
Going in at the land border also has very high chances. What I like about the land border is that you get to make a physical plea. Further more, at the land border you are guaranteed entry. Even if the officers begin the process to revoke your PR, you can still enter Canada by right and live during your appeal.
Having said the above, let me say this. From all the research I have done, there has never been a case where a minor (under 18) has showed up at the land border alone (without parents) and been issued a Departure Order. (The document which starts the process to terminate your PR.)
I believe the reason for this is that there is a difference in regulation concerning dealing with minor Permanent Residents. While for an adult, the officer at the land border can start the process to terminate your PR, if you are a minor, the officer cannot do that. They must refer you to the Immigration Division. (kinda like a legal hearing)
Only the Immigration Division can terminate your PR. (But as I mentioned above you have appeal rights, which can take years, and during the appeal you have the full rights of a PR.)
Because of these reasons, while as already mentioned chances of success with a PRTD are high, I believe chances are the land border are higher.
However, in exchange for receiving the slightly higher odds at the land border, what you trade is the ability to travel out of Canada for at least 2 years.
This means that even if there is a family emergency or something of that sort you cannot leave Canada without putting your PR status in jeopardy. You must make a personal choice on whether the marginally higher odds at the land border are worth not leaving Canada for 2 years.
Also, if you elect to go the land border route, you will not be able to renew your PR card for 2 years. Assuming you have your original record of landing and your SIN card, this shouldn't be an issue.
Another benefit of the land border is you get to save the PRTD processing costs and also don't need to deal with the processing time. (Which can take months in some cases.)
Should you elect to take the land border route, for maximum chances make your move to Canada before you turn 18, even if it's only a few days or even 1 day before your 18th birthday.
To clarify, and I cannot stress this with enough importance, while the land border offers higher chances, it is only by a very, very slim margin. For the slim increase in chances, you are accepting no travel for 2 years.
Is this a fair trade? That is your choice.
If are wondering what I would do, I would go via the land border. But that is just me. I t doesn't mean it is better, it is just what I would do.
Best of Luck!