How much marks is given for 22 months work experience?

It depends on the Institution that you want to join in. Look at few Institutions and their scoring for work experience:

IIM Ahmedabad:
Work Experience in Months            Rating Score

< 12 months                                                   0

>= 12 and <= 36 months                   MF * (number of months
of work experience  11)

> 36 months                                                        5

Work-experience Multiplication Factor (MF) = 0.20


IIM Bangalore:

The work experience score will be multiplied by the quality of experience score, as evaluated by the interviewing panel as an assessment of the relevance of the work experience to the program. The quality of work experience score will be evaluated on a 5 point scale (0.25 - 0.5 - 1 - 1.5 - 2) by
each member of the panel during the interviews. The average quality of work experience score will be multiplied by the pre-PI work experience score and accordingly the work or professional experience component score will be revised to arrive at a weighted work experience score.

IIM Calcutta and IIM Lucknow rate work experience on a scale of 5. Few IIMS like Kozhikhode, Sriamuar, Jammu do not need any work experience and so they do not have any marks allotted for work experience.

Hello, usually points are given according to your work experience. so you will get around 5 points.

Months.  Points

<6.                0

6-9.              0.5

10-12.          1

13-15.          2

16-18.          3

19-21.          4

22-24.          5

25-27.          6

28-30.         7

31-36.         8

37-39.         7

40-42.         6

>=43.          5

thankyou, I hope it helps, feel free to approach for further queries