ProxySG - How do I allow or deny certain download file size limits?

Examples of Regular Expression (Regex) syntax:

1MB (0 - 999999)

^[0-9]{1,6}$

2MB (0 - 1999999)

^[0-9]{1,6}$|^1[0-9]{6.EN_US}$

5MB (0 - 4999999)

^[0-9]{1,6}$|^[1-4][0-9]{6.EN_US}$

10MB (0 - 9999999)

^[0-9]{1,7}$

30MB (0 - 29999999)

^[0-9]{1,7}$|^[1-2][0-9]{7.EN_US}$

50MB (0 - 49999999)

^[0-9]{1,7}$|^[1-4][0-9]{7.EN_US}$

100MB

[0-9]{9.EN_US}[0-9]* 

150MB

1[5-9][0-9]{7.EN_US}[0-9]* | [2-9][0-9]{8.EN_US}[0-9]*

200MB

[2-9][0-9]{8.EN_US}[0-9]*

250MB

2[5-9][0-9]{7.EN_US}[0-9]* | [3-9][0-9]{8.EN_US}[0-9]*

300MB

[3-9][0-9]{8.EN_US}[0-9]*

300MB (0 - 299 999 999)

^[0-9]{1,8}$|^[1-2][0-9]{8.EN_US}$

 Steps:

1.     Open the VPM (Visual Policy Manager).

2.     Create or open a Web Access Layer.

3.     Create the following rule:
Source: Any, or user or group
Destination->New->Response Header->Content-Length and put in the desired Regex from the list above.
Action-> Allow or Deny.

If, for example, you want to ALLOW anything that is above 30MB, select the regex by doing the steps above. Then right-click the Destination box, and set it to NEGATE. This is required because the Regex represents content-length of 0 to 30MB; be negating this content-length, anything NOT between 0-30MB will be allowed.

Refer below Link

HERE