If you own gold in the form of jewellery it is advisable to get a gold loan. When selling gold jewellery you are paid only for the gold it contains and hence you lose out on jewellery making charges which form a significant part of jewellery cost when purchasing it. Jewellery making charges are simply not considered by the jewellers when buying gold jewellery back from their customers. Even while giving you a gold loan the loan providing company will only consider the quality and quantity of gold in the jewellery but here at-least you are assured that next time you do not waste any money on jewellery making charge again if you plan to buy the same type of gold jewellery thereafter.
If you own gold coins, gold bonds or gold ETFs it is recommended to sell them when in need of money as here you are paid more or less in full according to the market rate of gold or the ETF NAV. Also, there's no point in borrowing money for your financial need and paying interest on it when you already have it in your locker.