Is my router ready for 20 m/bit connection?

You can upgrade routers if you wish but if you want to see how fast the ROUTER goes try a lan speed test and unplug the modem or broadband connector then if it goes fast enough then its the internet connection you have if it stops at still 6 mbps then just upgrade to a 10/100 router ( they cost a lot less but still do what you want to do)