The letters show an intimate exchange between Gandhi and a South African Jewish bodybuilder and architect, Hermann Kallenbach, and were bought by the Indian government last year and put on display.
The two men lived together for two years after they met in 1904.
The display of the letters is the Indian government's allowance to show the complex nature of this world leader. Past books and writings suggesting Gandhi's gay affair were banned.
A recent book, "Great Soul: Mahatma Gandhi And His Struggle With India," written by former New York Times executive editor Joseph Lelyveld details the letters and the relationship.
In the book, the author points out:
* Gandhi slept in beds with young women under the age of 18, including his great-niece,
* Gandhi was in a long-term, gay affair with Kallenbach,
* Gandhi left his wife at one point to spend more time with Kallenbach,
In the letters, there are intimate moments from Gandhi, like:
"Your portrait (the only one) stands on my mantelpiece in my bedroom. The mantelpiece is opposite to the bed. . . . How completely you have taken possession of my body. This is slavery with a vengeance."