"As you are aware, Covid-19 has very severely hit the aviation industry and Trujet is no exception," the letter noted.
The airline said it is "facing serious financial crunch/cash flow situation".
"Though Trujet management was liberal in paying full salaries in the month of March and April, slight reduction in May and June, going forward, we need to take tough decisions, though unpleasant, in the interest of the survival of the company,” the letter noted.
"There is no clarity as to when the Covid pandemic will come into control and as per health and industry experts, it may take at least 12-18 months to recover fully," it added.
The aviation sector has been significantly impacted due to the travel restrictions imposed in India and other countries in view of the coronavirus
pandemic. All airlines in India have taken cost-cutting measures such as pay cuts, leave-without-pay and firings of employees in order to conserve cash flow.
India's largest airline IndiGo announced on Monday it has decided to lay off 10 per cent of its workforce.
India resumed domestic passenger flights from May 25 after a gap of two months due to the coronavirus
pandemic. However, the airlines have been allowed to operate only a maximum of 45 per cent of their pre-Covid domestic flights. Occupancy rate in Indian domestic flights has been around just 50-60 per cent since May 25.
Scheduled international passenger flights continue to remain suspended in India since March 23.