Nassar made his directorial debut with Avatharam (1995), a film based on the backdrop of a folk art troupe. Starring Revathi as his co-star, Nassar stated that the idea had come to him as a result of his childhood memories of watching theru koothu being performed on the streets alongside his father. The film won critical acclaim, but failed to become a commercially successful venture. Soon afterwards, he made Devathai (1997), stating he remembered a story he had first heard as a child, which became the "creative seed for this film" about reincarnation. He stated that his immediate busy schedule had subsequently cost him a role in Aamir Khan's Lagaan (2001). He subsequently continued to work in films in the late 1990s, portraying a blind musician in Rajiv Menon's Minsara Kanavu (1997), a political leader in Mani Ratnam's Iruvar (1997) and as the father of a pair of separated twins in S. Shankar's Jeans (1998).