First you need to take appointment online unless it is urgent. If it is urgent, you can go directly to PSK (passport Seva kendra) and there is a separate line for people without appointments. In our case, it is simple renewal/refresh. Passports were expired less than an year back.
Create a login at passport seva website ( http://www.passportindia.gov.in/AppOnlineProject/online/welcomeLink. ). Multiple appointments can be taken from one user id. No need to create one for everyone in the family.
Appointments open at 7.30PM on weekdays. If you login at 7.30 or after that, you will never get an appointment. I tired this for one month and was quite lost on how to proceed. There is no other way you can take an appointment and website keeps playing with you telling you comeback next day and try at 7.30PM. It is almost like government is laughing at your misery.
Fill the application or upload it to website and login few minutes before 7.30PM and keep clicking for appointment. It will keep rejecting after you choose PSK. Just ignore that and keep clicking. Magic will happen at 7.30 and it will show available slots, choose one and proceed. It will only show for one day.
If you have to take for multiple people, you won't get it if you try one after another. we tried from multiple PCs and was able to . Otherwise you will have to go on different dates.
For renewals, it was simple. We had to take only original passport and copy of it. Cash is accepted there for fee. Photos also not needed. They will take it there. Passports came exactly in one month for us.
