How many years does one need to get darshan of god? And how is correct "tapasya" done?one if my friends told me approximately 10 years are needed. Is it right?
One has to attain mental purity to succeed in sadhana.
For the attainment of mental purity, spiritual aspirants (Yogins) perform action, devoid of attachment, with their body, mind, intellect, or even merely with their senses.
The speed of attaining the necessary mental purity depends on the intensity of one's effort, the intensity of vairagya or renunciation and the state of one's mind, i.e., on the past karma. So one can not give in general any estimate of the time needed to succeed in sadhana or spiritual practice.