He will be cremated tomorrow in his native village in Jhunjhunu district of Rajasthan with full state honours.
The 86-year-old Congress leader from Rajasthan was suffering from various ailments for some time and was "chronically ill", sources in Medanta Medicity said.
The end came at around 3:30 AM at the hospital.
The Jat leader is survived by his wife, two sons and a daughter.
Ola had undergone an eye surgery and an intestine operation at the hospital where he was admitted since November, his family said.
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The Union Cabinet, of which Ola was a member since June 17, this year, also met at the Prime Minister's residence and mourned his death.
As a mark of respect for the departed leader, the national flag was flown at half-mast in Delhi and the capitals of States/Union Territories today, and tomorrow at the place where the funeral takes place.
The Cabinet also passed a condolence resolution and placed on record its appreciation of his services and deep sense of grief and loss at his demise, besides extending its condolences to members of his family.