Hi mr. singh,
I have retrieve information from CIC website about study permit requirements which are follows:
"In general, foreign nationals need a study permit to study in Canada. There are some exceptions. Find out more about who needs a study permit.
In most cases, you must apply for a study permit before coming to Canada. Ensure that you have a letter of acceptance from the designated learning institution in Canada that has accepted you before you begin the application process.
You can apply for the study permit at the Canadian visa office for your country, at a Visa Application Centre or online. Find out more about how to apply.
To study in Canada, you must have legal status. You also need to find out if you need a study permit.
If you don’t need a study permit: you can enrol in your studies, but remember that you must leave Canada at the end of the authorized period or apply to extend your stay as visitor.
If you need a study permit: you need to comply with the conditions and requirements of the International Student Program.
How to get a study permit
If you belong to one of the following groups, you need to apply to extend your stay in Canada as a student:
1. minor children studying at the primary or secondary level
2. exchange or visiting students
3. students who have completed a short-term course or program of study, which is a condition for acceptance at a designated institution
4. holders of temporary resident permits (TRP) valid for a minimum of six months and their family members
5. spouses or common-law partners (and their family members) who are in Canada and who have applied for permanent residency if they
have been deemed eligible to apply (first stage approval)
6. person whose study permit was authorized by a visa office abroad where the permit was not issued at a port of entry
7. family members of athletes on a Canadian-based team, media representatives, members of the clergy or military personnel assigned to
Canada
8. family members or a private staff member of a foreign representative who is properly accredited, may apply within Canada 90 days before or after they are no longer authorized to study without a study permit
9. foreign nationals and their family members holding a valid study or work permit
Remember that you can’t stay in Canada beyond the expiry date of your passport. If you renewed your passport since entering Canada, you have to submit photocopies of both your new passport and the stamp placed in your old passport.
All other applicants
If you don’t belong to one of the groups above, you must submit a study permit application. To apply, you must:
1. apply online or use a paper application in a country outside Canada where you are lawfully admitted, or
2. apply in person or by mail at the Visa Application Center in your Home Country or Country of residence."
So as you mention Mr. Singh that you heard that people on tourist visa apply study permit with the help of lawyer or attorney. Yes, as I highlighted No. 4 in Blue that "holders of temporary resident permits (TRP) valid for a minimum of six months and their family members." can apply study permit within Canada.
Hope it will help to understand it.