May wore the traditional Indian clothing as she visited the Sri Someshwara Hindu temple in Bangalore, the southern city which has become the IT sector hub of the sub-continent.
The PM went to India at the head of a 33-strong business delegation with the aim of bringing down barriers to commerce and paving the way for a free trade agreement following Brexit.
Speaking to Sky News at the end of her three-day visit, she said: "Leaving the EU presents us with a world of opportunities and I'm determined to seize them.
"That's why I'm here in India, delivering on global Britain. And I have to say the response has been very good.
"During this visit, we've seen £1 billion worth of deals being signed and we've come to an agreement with the Indian government that we will work together with them on developing our trade relationship for the future.
"What does that mean? It means more jobs, more investment in the UK, more trade for British businesses and that's good for everyone."
The first leg of Mrs May's visit, in the capital, New Delhi, was dominated by tensions over visas, with Indian PM Narendra Modi putting pressure on the UK to ease restrictions on students and skilled workers coming to Britain.
May announced new measures to make trips to the UK easier for senior business executives, and she offered to discuss improvements in the visa application process for Indian citizens in return for greater co-operation over the return of migrants who overstay their permission to remain.
But for the Prime Minister, trade has been the priority, with deals sealed during the trip expected to create more than 1,300 jobs in the UK.
May issued a warning on Monday of the risks of stagnation and falling incomes if the UK fails to make a determined push for new trade opportunities after Brexit.
"As Britain leaves the EU, we're determined not to turn our backs on the world but to forge a new, global, outward-looking role for ourselves," she told a business summit in New Delhi.
"Because we know from history what happens when countries do not embrace the opportunities of the world - they stagnate, they get poorer, they don't protect their people, they make them worse off."
May said she had detected real interest in India in doing more trade with Britain after its departure from the EU, which she aims to complete by 2019.
She told ITV News: "The message I've had here is that people actively want to do business with the UK."
"The message I'm getting is that everybody wants to build on the trade relationship that the UK has with India. They see opportunities and benefits for India and the UK going forward."
Although EU rules block the UK from entering formal negotiations on a free trade deal with India until withdrawal is complete, Mrs May has made clear she is determined to do the groundwork for an early post-Brexit agreement and to tackle barriers to trade which can be dealt with immediately.
Her trip has seen memorandums of understanding signed on intellectual property rights and the ease of doing business in India, and she and Mr Modi agreed to co-operate on cyber-security and tackling violent extremism online.
In Bangalore, she visited a Dynamatic Technologies factory where Indian workers assemble components machined in the company's Swindon and Bristol facilities for Airbus jets.
And she joined flag-waving children at the city's Stonehill Primary School to witness a flypast of Indian Air Force jets and helicopters in her honour.
The flypast was the first of its kind offered to a visiting head of government, and follows a similar display by the Red Arrows during Mr Modi's visit to the UK last year.
The Prime Minister had a garland of flowers placed around her neck as she arrived at the temple to the sound of musicians playing drums and horns.
The visit ended with Mrs May taking part in a Hindu blessing, drawing her hands together across the top of a candle flame and touching her eyes, in a traditional ritual. She was then given red powder to dab a single spot on her forehead.
She later welcomed plans for the Science Museum in London to host a season of exhibitions and events dedicated to Indian innovation next year as part of the UK-India Year of Culture 2017-18.
May said: "This celebration of India's rich culture and history of innovation is another clear demonstration of the close ties between our two countries."