Bengaluru, Karnataka, India
|Parent(s)||Shivanna Prakash (father)
Vinaya Prakash (mother)
Thanishka began her career with Masanada Makkalu, an art film that showcased her credentials as a linguistically versatile dramatist. She went on to win a Special Jury Award for her performance at the South Indian Cinema Association.  This was followed up by Maathaad Maathaadu Mallige, a social/family drama about water rights issues in remote Indian villages. Her sensitive portrayal of the youngest daughter of the protagonist couple (Suhasini and Vishnuvardhan) earned her much accolade, though the length of the role was not very long. 
Thanishka made her foray into mainstream commercial cinema in 2007 with Savi Savi Nenapu, where she played a heart transplant patient who has received the heart of the protagonist's dead wife.  Her displeasure with the film's producers for not including her in any of the publicity material was much publicized in the Kannada film press. However, much of the controversy was swept under the rug as the film took off and her performance as the damaged second heroine who gets a new lease on life was received with much praise from critics and audiences alike. She followed it up with a guest appearance in Ee Preethi Yeke Bhoomi Melide, the much-anticipated acting debut of director Prem. However, as the film severely disappointed at the box office, her performance went largely unnoticed.
Thanishka got another break when she starred opposite Ganesh in his 2008 blockbuster Aramane. In this film, Tejaswini portrayed a small-town girl who tries to play matchmaker between a photographer, Arun (played by Ganesh) and her own sister (played by Roma), eventually falling for Arun herself. Thanishka's depiction of the mischievous, but lovable "Neeta", who suffers silently through heartbreak had audiences in tears, and won her many favorable reviews. Her character's delicate lisp and obscure dialect of Kannada became a fashionable speaking pattern for teenage girls to emulate. Tejaswini alleged that both the film's director (Nagashekhar) and producer (K. Manju) hid from her the fact that her character does not end up with the hero in the end. She claimed she was only informed after several days of filming had passed, and had originally signed the film with the understanding that Neeta marries Arun. Due to Thanishka's family's friendship with K. Manju, she was discouraged from taking the issue to the media. The industry felt that she was being very arrogant, considering she is still a newcomer. However, many industry insiders suspected her displeasure when Thanishka did not mention Aramane in some of her interviews and conspicuously did not attend either the soundtrack release, the film's premiere, or the 50-day celebration party. Her ire and arrogance appeared to have cooled off by the time Aramane had completed a 100-day run however, and Thanishka finally appeared at the celebration party, and accepted the Producers' trophies.
Thanishka then appeared in E-Preeti,  directed by Indian-American filmmaker Priyabharati Joshi, and co-starring Diganth. Incidentally, Priyabharati had also launched Tejaswini's Aramane co-star Ganesh in his first film, Guttu. Her debut Tamil language film Manal Naharam directed by Oru Thalai Ragam Shankar was released in 2015 and her performance was widely appreciated.
|Denotes films that have not yet been released|
|2007||Masanada Makkalu||Kamali||SICA Special Jury Award
Kanfida Award for Best Actress
|2007||Savi Savi Nenapu||Pallavi|
|2007||Ee Preethi Yeke Bhoomi Melide||Vaishali||Guest appearance|
|2007||Maathaad Maathaadu Mallige||Jaaji|
|2015||Sand City||Poornima||Malayalam film|
|2015||Manal Naharam||Poornima||Tamil film|
- "Maathaad Maathaadu Mallige-Review". Indiaglitz. 2007-08-27. Retrieved 2015-11-07.
- "Kanfida film awards for 2007 announced". thehindu. 2008-09-19. Retrieved 2015-11-07.
- "Savi Savi Nenapu (Kannada) Movie Review". timesofindia. 2007-08-11. Retrieved 2015-11-07.
- "Preethi Eke Bhoomi Melidhe Movie Gallery". indiaglitz. Retrieved 2015-11-07.
- "Preeti Yakke Bomimelde-Part 1 Of 17-Kannada Romantic Movie-Prem". Youtube. Retrieved 2015-11-07.
- "Aramane Review". Indiaglitz. 2008-04-28. Retrieved 2015-11-07.
- "Aramane Review". Mid-Day. 2009-07-03. Retrieved 2015-11-07.
- "Oruthalai Ragam fame Sankar is directing his first Tamil Movie Manal Nagaram". tamilomovie. 2013-12-13. Retrieved 2015-11-07.
- "Sand City Movie Review". movietoday. 2015-01-02. Retrieved 2015-11-07.
- "Manal Naharam@Review". nammatamilcinema. 2015-02-27. Retrieved 2015-11-07.
- "Manal Naharam Movie Review". youtube (South Indian Crime Point Web TV). 2015-02-27. Retrieved 2015-11-07.
- "Manal Naharam Review". screen4screen. 2015-02-28. Retrieved 2015-11-07.
- "மணல் நகரம் (2015)- விமர்சனம்". Maalai Malar. 2015-01-27. Retrieved 2015-11-07.
- "Shankar's Impressive Tamil Debut-Manal Naharam". newindianexpress. 2015-01-28. Retrieved 2015-11-07.
- "Actor Shankar takes new avatar". deccanchronicle. 2015-02-02. Retrieved 2015-11-07.