No point in looking at the raw market cap, it needs to be adjusted by the “investable weight factor” IWF.
Refer to these docs for details of how to calculate.
https://au.spindices.com/documents/methodologies/methodology-sp-asx-australian-indices.pdf
https://us.spindices.com/documents/index-policies/methodology-sp-float-adjustment.pdf
Basically, if 50% of shares are held by insiders and significant shareholders, the market cap will be reduced by 50%.