We prefer YEM (yeast extract-mannitol) medium for culturing all Rhizobium species including R. meliloti.

Root nodule associated bacteria were isolated from the nodules of Fenugreek plants from different field areas on the YEMA/NA and rhizospheric isolates from the soil adhering to the roots of the plant were isolated on the Nutrient Agar (NA) medium.

Yes you can use Yeast extract mannitol medium for cultivation of Ensifer meliloti  (syn. Sinorhizobium meliloti, Rhizobium meliloti). Inoculate YEM broth with your bacterium and incubate at 28- 30 C for 48 hrs. The culture is ready for seed bacterization, deep fenugreek seed in the bacterial culture, shake it for 30 min.

Thank you Pravesh. would u please give me a reference for this protocol?

Make talc  based formulation of your desired bacterial strain. Also add any adherent like molasses or CMC. That will help bacterial formulation to adhere with seeds.      

I dont have reference for rhizobium but we did this type of inoculation for small plantlets of stevia check this article: Applied Soil Ecology 46 (2010) 222–229

Stimulatory effect of phosphate-solubilizing bacteria on plant growth, stevioside

and rebaudioside-A contents of Stevia rebaudiana Bertoni

doi:10.1016/j.apsoil.2010.08.008