OCI applicant

[ociappl]

I have the OCI application ready for mailing to the NY office. Once I submit the application, if If I have to travel to India before I get the OCI card, can I travel on my existing Indian Tourist visa?
Also, if I'm in India when the letter to send in my US passport comes,
can I delay sending it to the Indian embassy in NY?
Also, with my OCI application, can I send in my Indian birth certificate or should I send in copies of my Indian passport?

[immihelp]

1. Yes.
2. Yes.
3. Documents requirements at /oci-card/