Shrautaism
Shrauta communities are very rare in India, the most well known being the ultra-orthodox Nambudiri Brahmins of Kerala. They follow the "Purva-Mimamsa" (earlier portion of Vedas) in contrast to Vedanta followed by other Brahmins. They place importance on the performance of Vedic Sacrifice (Yajna). The Nambudiri Brahmins are famous for their preservation of the ancient Somayaagam, Agnicayana rituals which have vanished in other parts of India.
Read more about this topic: Hindu Sects