Can a OPT-H1b ( Filing 1040NR) ask for extension?

Can it be done by phone or needs paperwork

Which paperwork

Appreciated

You must file Form 4868. It can be efiled or paper form.
Instead of trying to complete your tax return in a rush, it is better to get an extension. Make sure that your return is error free.
Read Your U.S. Tax Return: Form 4868 Automatic Extension for 6 months (http://taxipay.blogspot.com/2009/04/form-4868-automatic-extension-for-6.html)