[3][4] Swarup was the founding director of the National Centre for Radio Astrophysics (NCRA) at the Tata Institute of Fundamental Research (TIFR).

[5] Under his leadership, a strong group in radio astrophysics was built at Tata Institute of Fundamental Research that is comparable to the best in the world.

[7][10][11] Swarup spent several years at the National Physical Laboratory in Delhi with K. S. Krishnan (1950–53),[7] measuring the spin resonance of electrons.

He worked closely with Pawsey, Wilbur Norman Christiansen, John Gatenby Bolton, Bernard Mills and others.

[11] He worked as a research associate at the Radio Astronomy Station of Harvard University at Fort Davis, Texas (1956–57).

Returning from Stanford to India in March 1963, Swarup joined TIFR as a reader at the request of Dr. Homi Bhabha.

[6][10] While at CSIRO, Swarup and R. Parthasarathy converted Potts Hill's L-shaped grating radio interferometer telescope to an operating wavelength of 500 MHz.

[13][22][23][24][25] Returning to India on April 2, 1963, Swarup began to assemble a group at the Tata Institute of Fundamental Research near Mumbai.

[26] The design was "unique and innovative",[13] "the first large equatorial cylindrical parabolic radio telescope with steerability in both directions".

[26][6] Occultation observations of Sagittarius A* at the Galactic Center of the Milky Way galaxy supported the separation of its emissions into two dimensions, thermal and non-thermal.

[8] GMRT was recognized as a key historical achievement in electrical and electronic engineering and given IEEE Milestone status in 2020.

[4][8][9] Membership of professional societies: Royal Society, London;[36][4] Royal Astronomical Society, London;[4] Indian Academy of Sciences;[4] Indian National Science Academy;[4] National Academy of Sciences, Allahabad, India;[4] Third World Academy of Sciences;[4] Indian Geophysical Union; Maharashtra Academy of Sciences; Institution of Electronics & Telecommunication Engineers; Indian Physics Association; Indian Physical Society; International Academy of Astronautics; Pontifical Academy of Sciences; Positions held: Astronomical Society of India (President 1975–77); International Astronomical Union (IAU) (President, Commission 40 on Radio Astronomy, 1979–82);[37] Executive Committee, Inter Union Commission for Frequency Allocation (IUCAF till 1995); IAU Working Group for Future Large Scale Facilities (1994–2000); Chairman, Indian National Committee for International Union of Radio Science (URSI) (1986–88 & 1995–97); Post-detection Sub-Committee of SETI of International Astronautical Federation (Chairman, 1994–98); Chairman, URSI Committee for Developing Countries (1996–2002); URSI Standing Committee for Future General Assemblies (1999–2002).

[13] Awards: 1973 Padma Shri; 1972 S.S. Bhatnagar, Council of Scientific & Industrial Research, India; 1974 Jawaharlal Nehru Fellowship for 2 years; 1984 P.C.