The Uncommon White Tara practice requires an initiation from a qualified lama to do the practice.
In Tibetan Buddhism, the practice of White Tara is a part of the daily meditations of all the adherents of all four traditions. The White Tara practice was transmitted into Tibet through four great traditions attributed to Atisha, Nyen Lotsawa Dharma Drak, Bari Lotsawa Rinchen Drak and Kasmiri Pandita Sakya Sri. As recipient of all these lineages in Tibet, Bari Lotsawa became the confluence of all the traditions.
Known as Dolkar Oser Drook Drak, or The White Tara Practice of six fold rays of light", the practice is highly respected as the uncommon White Tara practice in the Tsarpa Tradition.
It takes about an hour and involves chanting and visualisations which help transform our ordinary states of mind to generate enlightened qualities of compassion and kindness.
This practice is also known as a long life practice and again there are many legends of great yogi's who did this practice in retreat to increase their lifespan so they could continue their Dharma activities.