Ishtam is a romatic movie in which, Karthik (Charan) hails from a good and rich family. Neha (Shriya) is Subbu's daughter and she's motherless. Karthik is the senior of Neha in the college and rags her a lot. In the college Karthik rags her a lot.
Neha rescues Karthik's mother Lakshmi at an incident and brings her in hospital. Lakshmi and Neha become friends and Neha falls in love with Karthik. But when Subbu proposes to Karthik 's parents to arrange Karthik and Neha's marriage, Lakshmi refuses.
Rest of the movie is about why Lakshmi refuses their marriage.