Hi pradnya samant
Display OB for Periods
Displays the opening balance in one of the following specified ways:
- OB from Start of Company Activity– from day one of company activity through the date range defined for the report.
- OB from Start of Fiscal Year– accumulated from the start of the fiscal year to which the earliest posting period included in the date range of the report refers.
If the date range defined is 1.4.12–31.3.31 and the posting periods defined are four quarters per calendar year, the date to be considered as "Start of Fiscal Year" is 1.1.2013 .
The calculation of the opening balance is influenced by the date range defined for the report. If you specify more than one date range, SAP Business One calculates opening balance as follows:
- If Posting Date is one of the selected options, all transactions with posting date earlier than the date defined in the Posting Date From field are included.
- If Posting Date is not one of the selected options, all transactions with document date earlier than the date defined in the Document Date From field are included
Hope Helpful 
Regards
Kennedy