As you can see only the seal page is a little damaged. Other than that my booklet is in perfect condition. Do I have to apply for a new passport or would this be usable?
That is clearly a damaged passport, even the government seal is damaged. Forget everything else.
It is not a good idea to use it anymore. Luckily it is not damaged beyond recognition, it will be relatively easier to replace it.
Q6: My passport booklet is damaged. I want to go abroad on urgent basis. What should I do?
A: 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.