Hii,
please remove open bracket . highlighted in red mark
=IF(VLOOKUP(A7,'Fuel and Driver less than 13'!B4:AJ211,35,0)=0"",
( VLOOKUP(A7,'Fuel 13 and above'!B5:AI45,34,0)))
RECTIFIED FORMULA
=IF(VLOOKUP(A7,'Fuel and Driver less than 13'!B4:AJ211,35,0)=0,"",VLOOKUP(A7,'Fuel 13 and above'!B5:AI45,34,0))
thanks
rahul