In Hinduism, upatantras are minor texts attached to major Tantra works. A tantra work is defined as one that deals with tattva (science of cosmic principles) and mantra (science of mystic sound). Upa means supplementary texts to the main texts later on. The origin and development of the Tantras are ultimately connected with the rise of Shaiva Agamas and the Vaishnava Pancaratra Agamas (Vaishnava in character). This system is called rahasya amnaya, secret methods of sadhana.
In the first stage of Shaiva, Agamas are given the title of Tantras; in the next stage, the texts are called yamalas. Yamala type of Tantras and Upatantras introduced a new variety of sects of innumerable numbers of gods and goddesses. These included practices of local sects and opened up the field of tantric sadhana (practice of the tantric or mystic tradition) to the people of all four castes.
The Puranic Tantra is divided into four Shaiva, Vaishnava, Saura and Ganapatya. These have their Upatantras. In these Upatantras, japa, homa, and tarpana, which are the essential features of worship of a deity, are described.
Japa means repeating the mula mantra; japa to all the forms of gods are enumerated in these texts. Homa means offerings to the holy fire. Different kinds of offerings and mantras specific to each god are described in Upatantras. Japa is the best example for private worship, not even light is essential here. Homa is Vedic ritualism adapted to our requirements. Ganapati homam, sudarshana homam, mrityunjaya homam, etc., are performed by shareholders. According to these texts, tarpana means upachara or giving. At least five upacharas must be given to a deity daily.
Padya – Here water is worshiped and ‘vam’ is the mula mantra. This implies the acquaintance or relationship with the deity.
Gandha – Through this, the element prithvi is pleased. ‘Lam’ is the mula mantra. By applying sandal paste to the ishta devata, trust in God is established. Here God becomes our master.
Dhupa – The element vayu is pleased with incense. ‘Yam’ is the mula mantra. Bhakti (devotional love) is established, and God becomes a possession.
Dipa – Fire is worshiped. ‘Rum’ is the mula mantra. Here the devotee gets jnana (knowledge).
Naivedya – It is the final upachara, where the mula mantra is ‘vam’. Here is the devotee identifies himself with God.