The annual Navratri Brahmotsavam celebrations 2015 in Tirumala Tirupati Balaji temple will begin on October 13, 2015 and end on October 22, 2015. During the nine-days of the Brahmotsavams, Sri Venkateswara will be taken in procession around the temple in different Vahanas (special decorated Vehicles based on Vishnu legends). There will be special Unjal Seva during the period.
October 14, 2015 – Dwarjarahanam (Morning) Pedda Sesha Vahanam (Evening)
October 15, 2015 – Chinna Sesha Vahanam (Morning) Hamsa Vahanam (Evening)
October 16, 2015 – Simha Vahanam (Morning) Muthyapu Pandiri Vahanam (Evening)
October 17, 2015 – Kalpa Vruksha Vahanam (Morning) Sarva Bhoopala Vahanam (Evening)
October 18, 2015 – Mohini Avatharam (Morning) Garuda Vahanam (Evening)
October 19, 2015 – Hanumantha Vahanam and Swarna Ratham (Morning) Gaja Vahanam (Evening)
October 20, 2015 – Surya Prabha Vahanam (Morning) Chandra Prabha Vahanam (Evening)
October 21, 2015– Rathostavam (Morning) Aswa Vahanam (Evening)
October 22, 2015 – Chakra Snanam (Morning) Dwaja Avarohanam (Evening)
More information about various Vahanas during Navratri Brahmotsavam can be found in this earlier article.