During the Burmese invasions of Assam (1817–1826), Maniram's family sought asylum in Bengal, which was under the control of the British East India Company.

[5] Maniram became a loyal confidante of Purandar Singha, and resigned from the posts of sheristadar and tehsildar, when the King was deposed by the British.

It was Maniram who informed the British about the Assam tea grown by the Singpho people, which was hitherto unknown to the rest of the world.

Some of the markets established by him include the Garohat in Kamrup, Nagahat near Sivasagar, Borhat in Dibrugarh, Sissihat in Dhemaji and Darangia Haat in Darrang.

In 1851, captain Charles Holroyd, the chief officer of Sibsagar seized all the facilities provided to him due to a tea garden dispute.

[10] He wrote that the people of Assam had been "reduced to the most abject and hopeless state of misery from the loss of their fame, honour, rank, caste, employment etc."

He pointed out that the British policies were aimed at recovering the expenses incurred in conquering the Assam province from the Burmese, resulting in exploitation of the local economy.

Maniram further wrote that the "objectionable treatment" of the Hill Tribes (such as the Nagas) was resulting in constant warfare leading to mutual loss of life and money.

He also disapproved of the appointment of the Marwaris and the Bengalis as Mouzadars (a civil service post), when a number of Assamese people remained unemployed.

[12] To gather support for the reintroduction of the Ahom rule, Maniram arrived in Calcutta, the then capital of British India, in April 1857, and networked with several influential people.

[14] The conspirators were joined by the Subedars Sheikh Bhikun and Nur Mahammad, after Kandarpeswar promised to double the salary of the sepoys if they succeeded in defeating the British.

They planned a march to Jorhat, where Kandarpeswar would be installed as the King on the day of the Durga Puja; later Sivasagar and Dibrugarh would be captured.

Based on the statement of Haranath Parbatia Baruah, the daroga (inspector) of Sivasagar, Maniram was identified as the kingpin of the plot.

[15] Maniram's death was widely mourned in Assam, and several tea garden workers struck work to express their support for the rebellion.