Uruli Kamazhthu in Nilavara (offering of traditional bronze vessel) is one of the most popular devotee offering in Mannarasala. Known for begetting children to couples, thousands of people come here to carry out this sacred and rare offering to Nagaraja.
According to temple sources, there are certain strict rituals to be followed for this offering. It is advisable only for married couples who have not been able to have children for years, since their marriage.

The couple should come to the temple and pray to the God for his blessings. Receipts for the offering have to be taken from the administration office. Offering includes a bronze Uruli that can be used to cook at least a score of rice, a Nilavilakku (bronze lamp), garland etc. In the presence of the temple authorities, the couples should offer the Uruli with its mouth upwards in front of the Nagaraja shrine after three rounds to the temple with due prayers. An offering have to be given to Sarpayakshi as well. After Pooja, Valiamma will take the Uruli to Nilavara and it will be kept there with its mouth downward, which will be opened only after the couples get a child. Expenses for this offering are charted in a way to offer at least two Kadali fruits every day to Nagaraja, for about one year.

Once the couples are blessed with child, they should come to the temple with the child for prayers. They should submit either silver cradle or a miniature baby in gold or a miniature divine serpent in gold to the Nagaraja, in accordance to their financial abilities. Then Valiamma will open their Uruli kept in the Nilavara after due prayers.

According to temple sources, devotees can source all that are required for this offering from the temple administration office at nominal costs. Normally more than 5000 Urulis are offered in a year at this temple.