[6] He graduated (BSc) from the Punjab University in 1960 after which he started his career by joining the Bhabha Atomic Research Centre Training School.
[9] While at BARC, he did research under Rajagopala Chidambaram, the renowned nuclear physicist who would later become his associate in the Pokhran tests, and secured a doctoral degree (PhD) from Mumbai University in 1970.
His research during this period were centered around the topics of neutron diffraction, X-ray crystallography, and high pressure and Shock wave physics.
[9] He served BARC till 2002, holding several key positions such as that of the Director of Atomic and Condensed Matter Physics Group.
Sikka's early research on neutron diffraction and his studies of the Phase problem employing anomalous and direct scattering methods have been accepted by the International Union of Crystallography and has been incorporated in their teaching aids.
[11] It is reported that Rajagopala Chidambaram, his mentor at BARC, entrusted the responsibility of the development of the thermonuclear test device to Sikka,[12] after consultation with the then Prime Minister of India, P. V. Narasimha Rao.