If you do not need a visitor visa to enter Canada, you can still use the parent and grandparent super visa to stay in Canada for up to two years.

Complete and submit the requested documents to prove your eligibility. If we approve the application, we will issue you a letter to give to a border services officer when you arrive in Canada. In addition, if you travel by air, you need to apply for an eTA separately to allow you to travel to and enter Canada. The eTA will be electronically linked to your passport, so you need to travel with the passport you use to apply for your eTA, and your letter to facilitate your travel to Canada. The officer at the border may approve a visit to Canada for up to two years.

You will need a Medical exam to enter Canada with a parent and grandparent super visa. A Canadian immigration officer will send you instructions about what to do.

You may have to go for visa interview.

Minimum Requirement for Super Visa
In order to obtain a super visa, you will need to apply at a visa office and provide:

a letter of invitation from your child or grandchild residing in Canada. You must also include your host child or host grandchild’s family composition (dependants, including spouse, children or other relatives that are financially dependent on your host child or host grandchild).
one of the following documents to prove that your child or grandchild meets the Low Income Cut-Off (LICO)minimum:
Most recent copy of the Notice of Assessment. If you do not have a paper copy of your Notice of Assessment on file, you can view (and print) your tax returns as well as other personal tax information using the CRA’s My Account online service.
Most recent copy of the T4 or T1
Original letter from employer stating title, job description and salary
Employment insurance pay stubs
If self-employed, a letter from an accountant confirming annual income
Proof of other sources of income (pension statement, investments, etc.)
evidence of the parent or grandparent relationship to the Canadian citizen or permanent resident you wish to visit (e.g. birth certificate, baptismal certificate or other official documents naming you as parent or grandparent)
proof that you have private medical insurance valid for a minimum of one year from a Canadian insurance company and that:
covers health care, hospitalization and repatriation,
provides a minimum coverage of $100 000, and
is valid for each entry to Canada and be available for review by a port of entry officer.
You may be required to appear in person to have your biometric fingerprints and photo (biometric information) taken at a biometric collection service point.

You will be required to undergo a medical examination.

Apply online for Supervisa
Create your account on CIC web portal, there you can see multiple options to apply for visitors visa. Fill the application online. You need a valid credit card to make the payment for the visa. You have to upload all your required documents and also with the medical report and get a medical insurance for the parent/ grandpraent. The next step will be you have to go for an interview with the visa officer.