What to reply a PhD supervisor who says my chances of getting selected in this scholarship program are not very high? I sent an email to a professor and asked him if there's any PhD  position available in his group. I also told him that I want to apply for SINGA scholarship program if he agrees to supervise me.

The professor replied: 


  My experience with the SINGA program is that it is very competitive.  Almost all successful applications have already published papers prior to application.  I do not believe your chances for getting accepted are too high.


I really want to give it a try. How should I reply to tell the professor politely to please support my application, and that I don't care if I get a rejection from SINGA scholarship program?

Also, I am writing a research article, and I am hopeful it will be complete within two weeks.
The professor is saying no. He is being polite about it, but he's saying he doesn't want you in his group. Arguing with him is not going to change that. (In fact it's more likely to solidify in his mind that you are a bad candidate, with poor social skills, who would be a poor fit in his program.) 

Look for somewhere else to go.