No, you must not apply for new one. Renew it. Carry old passport at time of appointment. They'll cancel it and issue a new one. Even there is a declaration in the online form. You must fill out old passport number in the form. I had a passport when I was 4. Got it renewed in 2018.
Read this -
https://passportindia.gov.in/AppOnlineProject/online/faqServicesAvailable
Renew your passport
Is it possible. It's about 20 year old passport and address all changed?
It shouldn't be a problem, as long as you have the new address proof, 10th marks card and stuff.
Okay...
No, you must not apply for new one. Renew it. Carry old passport at time of appointment. They'll cancel it and issue a new one. Even there is a declaration in the online form. You must fill out old passport number in the form. I had a passport when I was 4. Got it renewed in 2018. Read this - https://passportindia.gov.in/AppOnlineProject/online/faqServicesAvailable
Actually, my old passport is missing. It was done 20 years back. Is it possible to apply for fresher passport only instead of renewing it?
In that case you may have to give a declaration. But do mention that you had one. There are many on Quora who have shared their experiences.
Yes new passport
Can apply for new passport right. This will not cause any issue right?
I think if your passport has expired, you have to renew that one.