Member failing due to Critical Sec. 9.3.2.2

I Need Help in Resolving Failure of Member.
This is a tapered I section, but it is failing under clause 9.3.2.2. of IS800.  Can anyone help me to resolve this critical condition  ?
Flange thickness is 12 mm
Other details of section in photo.

5826.IS 2.1.STD

Thank You in advance.