1. Dear member, you have not mentioned as to whether your question relate to claim of maternity benefit under ESI Act, 1948 or under the Maternity Benefit Act, 1961. In case you are not covered under ESI Act, 1961, you can claim said benefit under the Maternity Benefit Act, 1961 provided you are eligible for the same.
2. I think, the procedure to claim benefit under MB Act, 1961 must have been explained in the Rules as framed by the appropriate State Govt. where you are residing. In case you are residing in Karnataka, I hope Maternity Benefit Rules as framed by Karnataka State Govt. will be applicable. For more details, you can get a copy of the same from any law-book shop of the area. So far as I understand, you are required to obtain Medical Certificate on prescribed form (as per said Rules) and submit your application/intimation or notice to your employer on prescribed form. I think, to certify as to from which date a woman is required absentation from work due to confinement/miscarriage etc. is a medical issue and is to be certified by the competent Medical Officer/Medical Practitioner as laid down under said Rules.
3. I think, about all above procedure, you can also confirm the position from concerned HR/HR department of the organisation where you are working.
With best wishes.