Can an old man from China go to Italy to take his grandson to rent a house?

Of course. The rental contract of Italian relatives, if it is their own house, provide a copy of the purchase contract, residence and passport of Italian relatives. If the expenses during visiting relatives are borne by relatives in Italy, you need to provide the bank flow in Italy in the last three months, cud and the last three months. If you bear the expenses during your family visit, you need to provide your own income certificate and bank deposit certificate in China.