Explanation:

 Rajasthani Standard: the common lingua franca of Rajasthani people and is spoken by over 18 million people (2001) in different parts of Rajasthan. It has to be taken into consideration, however, that some speakers of Standard Rajasthani are conflated with Hindi speakers in the census.

Main folk languages :

Marwari: the most spoken Rajasthani language with approximately 45 to 50 million speakers[citation needed] situated in the historic Marwar region of western Rajasthan. The 2001 census, however, records only 15 million speakers. Like Standard 
Mewari: approximately 5 million speakers in the Mewar region of Rajasthan.
Mewati: approximately 3 Million speakers in the Mewat and Ahirwal regions, comprising Haryana, Delhi and Rajasthan.
Bagri: approximately 1.4 million speakers in northern Rajasthan and northwestern Haryana. There are also speakers situated in southern Punjab