What is the rule for the 1 time extension granted on basis of having a Thai child ?

if you posses a non-o , are you given a 1 month extension ? or is it a 6 month extension ?

Please advise

You can choose from two types of extension, clause 2.18(5) or clause 2.24 of Police Order 777/2551 and Immigration Bureau Order 305/2551. See which one suits you better.

You can either apply for a 60 day extension or a 1 year extension.

If you apply for a 1 year extension you have to have either 400k in a Thai bank in your name only and it has to be seasoned for at least 2 months, or proof that you are receiving at least 40k/month income.

If you apply for the 60 day extension, no financial proof is required.

Unless you are the legal father of your child by marriage or legitimization the longest extension you can get is 60 days.

Info about legitimizing your parenthood here: http://www.thaivisa.com/forum/topic/381917-how-to-gain-parental-rights-as-a-father/