Answer
The answer is "Teesri Manzil". Shammi Kapoor's most notable film of 1966 was "Teesri Manzil", a comedy-thriller directed by Vijay Anand. The film starred Shammi Kapoor, Asha Parekh, Prem Chopra, and Helen, and featured music by R.D. Burman. "Teesri Manzil" was a critical and commercial success, and is considered one of the classic films of Indian cinema.