The mother-in-law of British Prime Minister Rishi Sunak was on Friday appointed to serve in India's parliament, capping a career working for the philanthropic arm of her billionaire husband's tech firm.

Sudha Murthy, 73, is the former chair of the Infosys Foundation, the philanthropic arm of the global tech behemoth Infosys her husband N.R. Narayana Murthy co-founded in 1981.

The couple's daughter Akshata married Sunak in 2009.

Indian Prime Minister Narendra Modi said he was "delighted" at Murthy's nomination to the upper house, announced by President Droupadi Murmu.

He said in a social media post that her "contributions to diverse fields including social work, philanthropy and education have been immense and inspiring".

Most members of India's upper house are elected but 12 of them, usually high achievers in public life, are nominated to the chamber by the president for a six-year term.

Murthy's appointment takes immediate effect.

An engineer by training, Murthy is also a feted author and her foundation is credited with establishing libraries in rural areas.

The Indian government last year bestowed Sudha with the Padma Bhushan, India's third-highest civilian honour, for her career in social work.

Her husband Narayana has an estimated net worth of $4.7 billion, according to Forbes.

In the past he has said he needed to borrow money from his wife to start his firm, now India's seventh-largest by market cap and the first Indian company to be listed on the New York stock exchange.

Sunak, 43, became the first British prime minister of South Asian descent in 2022 -- a milestone year for India's relationship with its former colonial ruler.

That August marked the 75th anniversary of India's independence from Britain, weeks before the South Asian country overtook Britain to become the world's fifth-largest economy.