My Indian passport has got some slight water mark in it now. Is this considered damaged passport or will it be fine. The pages which has my details are all intact. It is just the first page cover and slightly on the edges. Will I need to get a new one replaced. I have a visa appointment on Monday :(
Check the link in Traveller's answer carefully.
They don't define what a "damaged passport" is, but they distinguish between "just damaged passport", where the passport number and name are readable and the photo is intact, and "damaged beyond recognition", where that is not the case. You passport is not "damaged beyond recognition". Whether it is considered damaged is not clear from that site.
Important quote for you: "In case your passport has not been damaged beyond recognition, i.e. passport number is legible, name is legible and photo is intact, then you can apply for re-issue of passport under the Tatkaal scheme. But, if passport has been damaged beyond recognition, then you cannot apply under the Tatkaal scheme. In that case, you need to visit Passport Officer at your nearest Passport Seva Kendra to get the passport on urgent basis." So getting a new passport is easier for you, the same site has a link for "re-issue of passport.
It looks to me that they mean something much more serious with "damaged". For example, if a page inside was torn out - that would count as damaged. Your passport still contains all the information that it is supposed to contain, so it should not cause you problems at a visa interview. You might be told to bring a new passport when the visa is issued,
According to https://portal1.passportindia.gov.in/AppOnlineProject/online/faqLostDamagedPassports the definition of a damaged passport is:
Passport number is readable, name is legible and photo is intact
Damaged beyond recognition
Based on your question, your passport seems acceptable.