Thanks for your response Finikiez. IN this case I had to go through these patches as the latest one would not install straightaway.
1) ESXi550-201501001.zip
2) ESXi550-201505002.zip
3) update-from-esxi5.5-5.5_update03.zip
4) ESXi550-201512001.zip
5) ESXi550-201601001.zip
6) ESXi550-201602001.zip
7) ESXi550-201608001.zip
8) ESXi550-201609001.zip
So, it doesn't appears that these updates are cumulative.