stress to yield strength ratio

I will check and let you know.

STAAD can check the yield criteria given in Cl. 6.2.1(5) of EN 1993-1-1:2005. For this, you need to use a design parameter TORSION 1 when you set up the CODE CHECK for EC3. In this case, eq. 6.1 of the code will be checked and the result will be reported in the Output file. More details can be found in te International Design Codes manual chapter 8C.5.4.1 Basic stress check.

Yes but it reports for individual criteria eg., tension, bending etc separately.

But I want it for combined loading for given combination.

for example beam subjected to axial tensile load and bending will result in max tensile stress in bottom flange.

This stress value is reported in post-processing mode under beam>stresses>max stresses, but i was concerned with its ratio with yield strength.

Is it possible with STAAD?

I am not familiar with Eurocode but generally speaking, as part of the design output, STAAD.Pro reports the capacities for each member including capacity in tension. So you would know the force in the member and the capacity and hence the ratio.