Microalgal biomass is an enhanced resource of energy and competent in meeting the universal demand for fuels in transports. It appeared as solitary of the most encouraging origin for the production of biofuel. The current study concerned the prevalence of Cyanobacteria, and Green algae from fifty water and algal sample of paddy fields of Rasipuram, Namakkal district, Tamil Nadu, India. An entirety of 262 cyanobacterial taxa of 25 genera delineating 7 families and 157 taxa of green algae of 23 genera depicting 15 families were documented. Among them, the dominant species reported were Oscillatoria sp. Synechocystis sp. Aphanocapsa sp. Scenedesmus sp. Spirogyra sp. and Chlamydomonas sp. Among the 25 genera of cyanobacteria, 6 were heterocystous and 19 were non-heterocystous. Among them, the dominant and fast-growing microalga was identified morphologically as Synechocystis sp. The microalgal growth rate, chlorophyll, carotenoids, and phycobilins were resolved. The microalga was executed with 16 s rRNA amplification, sequenced, and NCBI BLAST seek was accomplished, showed 99% similarity, and identified as S. aquatilis strain mn27. It was deposited in Genbank and KY120320 is the accession number. The tree of Phylogeny was inferred through the approach of Neighbour Joining with MEGA 5. The content of hydrocarbon in S. aquatilis was executed with GC-MS. The chief hydrocarbons were Dibutyl phthalate and Ethanol, 2,2′-oxybis-. Microalga is a gainful choice for the production of biofuel, while its accessibility, inexpensive, simple to cultivate, and curtail Carbon dioxide emission in the ambiance. Microalgal biomass is one of the greater resources of energy.