I'm not sure what you are asking.
You have a tank 120cm long x 30cm wide x 70cm tall. If you mean what volume of water does it hold, that's 252 litres. But that would be right to the rim; you have to have a space above the water or it would overflow. Then the decor etc would displace some water, so the tank would actually hold less than 250 litres.
You had a thread about silver arowanas which was removed. This tank is far too small for an arowana - they need an absolute minumum of 180 x 90 x 90cm, that is a volume of 1500 litres.
