The full form of TMC is: THOUSAND MILLION CUBIC FEET

What does TMC mean?
TMC stands for Thousand Million Cubic Feet and is generally used to measure the volume of water in a reservoir. It is also used to measure the inflow and outflow of a dam.
1 TMC = 2831 crore litres = 7478711000 gallon
How do I calculate 1 TMC water?
TMC means a thousand million cubic feet
One Cubic Feet = 1ft x 1ft x 1ft = 0.3048 m x 0.3048 m x 0.3048 m = 0.02831684 m3
We know that 1-metre cube is 100 litres
Therefore thousand million cubic feet is 0.02831684 x103 x 106m3 or 28.3164 x 109 litres.