Round off amount can be added separately in the sheet as per your need and it can be map in Suvit. Below is step by step process to follow.
Round off column should be added. Round off amount should proper Minus "-"symbol should be added in excel sheet wherever required.
In "Ledger Mapping", the sheet header will be shown and against at it, simply select the tally round off ledger. Then click on "Save & Proceed" available in the bottom most right corner.