Dear student
Here, the meaning of 1/6th carried to reserve is that 1/6th portion of profit or something is transferred to reserve a/c.
For eg:- If a firm earns profit of rupees 30,000 and given 1/6th of it carried to reserve then it means that 1/6 of 30,000 that is 5,000 is transferred to reserve a/c.
Regards