You will need to complete the application form and submit it at the Visa Application Centers for Greece in India. For a complete list of VACs click here
Under the new visa system (link to VIS document) implemented by all Schengen missions in India as of November 2, 2015, all VIS visa applicants must submit their application in person in order for their biometric data (10 fingerprints and digital photo) to be taken.
Please note that appearance in person for all applicants regardless of age is mandatory for biometrics. Subsequent Schengen visa applications within 5 years may be submitted through authorized representative only if the applicant has a Schengen visa VIS.
Visa applications should be lodged no later than 15 calendar days prior to departure. Applications may be submitted at the earliest 3 months before departure.
For further details, please consult the following notice from the Embassy of Greece:
Important notice: When an applicant is requesting a visa for purposes of travel other than business, in addition to the below list of required documents, a personal cover letter with original signature should be submitted, stating the reasons for the trip, the travel itinerary, the duration of the trip and other important information regarding the travel.