dear aspirant,

The lingusistic minority is defined to the people  who speak languages who has mother tongue other than regional language and minority in population.

if you take maharashtra the linguistic majority are the marathis and minority would be HINDI speaking or gujarathi speaking population.

In case of karnataka, the minority languages can be Urdu, Telugu, Tamil, Malayalam, Marathi, Tulu, Lamani, Hindi, Konkani and Gujarati.

 Hence  it varies in different colleges depending on their location. Whereas some of the national level colleges like AIIMs don't have any quota like this. 

hope it helped.