Some help interpreting formula variables in Texas Instruments TPS565201 Buck regulator datasheet
For switching regulator designs, especially as a less experienced designer, I would recommend sticking closely to the datasheet, reference designs, and, in the case of TI, you can use their WebBench tool. Note that \$L_\mathrm{O} = L_\mathrm{out}\$. The values are defined on the first page of the datasheet:

In your case, \$V_\mathrm{out}\$ is \$6\ \mathrm{V}\$, so according to Table 2, you should choose \$L_\mathrm{out} = 3.3\ \mu \mathrm{H}\$ and \$C_\mathrm{out} = 44\ \mu \mathrm{F}\$. That capacitor value is two \$22\ \mu \mathrm{F}\$ in parallel, mentioned just above section 8.2.2.3. Given those values, you can find the peak current in the inductor to choose the right one.