It is not recommended to get a monkey as a pet, due to their complex needs and specific diet. Monkeys are wild animals and require special guidance and care.
In most countries, it is illegal to keep a monkey as a pet. Even those countries that allow it require licences and veterinary care. Therefore, if you wish to get a monkey as a pet you must check local laws, consult with a veterinarian familiar with primates, and acquire a permit or license.
Additionally, owning primates can be expensive for the owner as they require dedicated housing, special cages, special diets, and toys to keep them entertained. Monkeys require a lot of attention from the owner and cannot be treated as most other house pets.