After the ceremony, which takes place on the first day of Onam festival, the two will on Sunday evening head for former union minister Tharoor's parliamentary constituency of Thiruvananthapuram.
They will then wing their way to Dubai for a reception and move on to Spain for a short honeymoon.
A close aide of Tharoor said the MP was arriving in Coimbatore on Saturday and will drive down to his ancestral home. Dubai-based Pushkar, daughter of a retired Kashmiri soldier, is coming separately.
"Pushkar is coming by another flight and her stay for the day is at another place near here," the aide said.
Tharoor's 200-year-old ancestral home has been given a fresh coat of paint and a marquee has also come up in front.
"The wedding will take place Sunday according to Hindu Nair customs at 7.30 am in the presence of his grandmother. Only close relatives and friends of Tharoor will be present."
According to custom, Tharoor and Pushkar will be man and wife when he ties the 'thali' around her neck, exchanges garlands and hands her 'podava' or a new set of clothes.
This will be his third marriage.
The couple have hectic days ahead. They will leave by road for Coimbatore to take a flight to Thiruvananthapuram.
"They will arrive in Thiruvananthapuram late Sunday and stay at his rented flat in the city. On Thiru Onam day (Monday) at 10 am, there will be a get-together of select invitees.
"Then the next programme would be a reception in Dubai. From there they move on to Spain and on Sep 3, a dinner will be held for their friends in Delhi," said the aide.
Incidentally, the last Onam for Tharoor too was a memorable one. For the first time in five decades, he celebrated the festival in Kerala by having the traditional Thiru Onam lunch at an orphanage here.
Tharoor, 54, was born in London but has his roots in Palakkad. He had his school education in Mumbai and Kolkata and secured a Bachelor of Arts degree in history from St. Stephen's College, Delhi. He completed a Ph.D. at the Fletcher School of Law and Diplomacy at Tufts University, Massachusetts.
Tharoor, a former under secretary general at the UN, won by a record margin of nearly one lakh votes from the Thiruvananthapuram Lok Sabha constituency in 2009.
He resigned as a minister of state of external affairs following a controversy over the Indian Premier League.