Hello Ankur,
blank lines and visible rows are managed in WDDOMODIFYVIEW method from V_CONF_DOTC_BASIC view (WDC /SAPSRM/WDC_DOTC_CONF_OID).
You could enhance spot WD_BADI in order to create implementation for BAdI definition WD_BADI_DOMODIFYVIEW.
Then in method WDDOMODIFY, use method SET_ATTRIBUTE from context element interface for BLANK_LINES_COUNT and VISIBLE_ROW_COUNT elements in order to change values according to your needs.
Regards.
Laurent.