What does a Hindu achieve through sanyas?
The fourth and last stage of life is sanyas - a very significant period of life. According to Hindus, there are four basic aims of human existence. The first, dharm relates to discharge of one's duty. The second, arth relates to acquiring of wealth. The third, kam relates to gratification. And the fourth, moksha relates to final salvation. Sanyas is the stage to achieve moksha.
Moksha aims at giving up desires and attachment. Whatever one needs to do to achieve this aim is sanyas.
In the Manusmriti, 6/33, it is said:
In the fourth stage of life one must give up all kinds of attachments and accept sanyas.
After living a householder's life from 25 to 50 years age, when one's activities are greatly influenced by the senses, it is not easy to rise above passion and desires. Therefore, the third stage of life from 50 to 75 years, vanprasth is devised to gradually detach oneself from desires. At this time, the wife continues to give company to a man even while desires are gradually controlled as one prays and conducts yagyas. One makes efforts to repay the debts of society. After success at this stage, one is ready for sanyas.
In the Manusmriti, 6/35-36, it is said: