If your Live Account is in Bitcoin (BTC), your MetaTrader's balance will be in BITS.
If you would like to create a Live Account in BTC, you would simply need to choose the BTC option when creating your Account.
Your MetaTrader's balance will show in BITS.
1BIT is the sub-unit of a Bitcoin. For instance, when comparing to USD currency, 1BIT would be an estimate of 1Cent of 1USD.