Balance of payments is a systematic record of all economic transactions which are occuring between normal residents of reportin countries with rest of the world during an accounting year. Deficit in Balance of Payments means that the sum of credit side of balance of payment is lesser than the sum of debit side of balance of payment. (or in other words sum of balance on current account and balance on capital account is negative). Which means inflow of currency is lesser than outflow of currency. That means that receipts of foreign exchange is lesser than the payment obligations. Which means we have to arrange foreign exchange to meet out this gap.
Causes responsible for this deficit are increase in imports, decrease in exports, large scale outflow of foreign capital and decrease in inflow of foreign capital, etc.
This deficit can be meet out through by selling gold in international market, by using reserves of foreign exchange held by Central bank or borrowings by Government from IMF.