Please can you tell me how I make the biomass as renewable and to includes it on the renewable fraction.

You can use HOMER to model biomass in two ways:

1.  If the supply of biomass feedstock is abundant throughout the year, the easiest thing to do is to simply define your own fuel (using the New button in the Generator Inputs window) to represent the biomass fuel.  For example, you could define a fuel called "Landfill gas" with a carbon content of zero (or less than zero if you want to account for the avoidance of methane emissions and their consequent greenhouse potential) and then specify that your microturbine (or other generator) consumes that fuel.  Use the generator's two fuel curve inputs (slope and intercept) to specify how efficiently the generator burns the fuel.

2. If the supply of biomass is constrained for all or part of the year, choose "Biogas" from the list of fuels for a particular generator, and when you hit OK the biomass resource button will appear in the schematic.  You can indicate the availability of the feedstock on a monthly or hourly basis.  We designed the biomass resource window with biomass gasification in mind, so if you are planning to use direct combustion or pyrolysis, you may need to adjust some of the inputs.

If you use option 2, HOMER will recognize the biomass-derived electricity as renewable, and the renewable fraction will reflect the biomass contribution.  But that's not true if you use option 1.