Maintenance

You have following remedies available; 

1. Seek divorce from him. Reason: He deserted you, he is not interested in you nor in his child for no reason and rhyme. 

2. Seek maintenance for yourself (if you are not qualified and not working/worked before) and for the child. Reason: You have meager rent for survival and child is in good school and not much money in hand for continuing lifestyle that you and child were used to.

3. Right to residence. Reason: You and child are destitute in eyes of Law. 

4. File DV Complaint against In Laws.Reason: For a foreign returned DIL in-Laws are  misbehaved persons.

5. How much you can claim que.; the draft reply is MOON is the limit.  Reason: From your brief you tell me when you stayed with him overseas you say you never knew his earning so it is again drafters natural response while drafting a suit plain matter for you that when your husband came to India you again didnot knew how much he earns and lastly when he left for overseas it is but natural to tell ld. Judge via your petition that I still donot know how much my husband earns !  In my opinion ld. Judge will use his discretion, donot worry there are others too in same category like you and you are not alone who after spending ages with their husband still donot know how much husband earns.

You might be a matrimonial dispute woman.

I suggest Section 125 cr.p.c. petition.  You give as much information about his employment, designation, the name of the company etc. along with his immovable property here in your petition.  Similarly your expenses and child's expenses also be mentioned.  If he does not turn up the court will grant ex-parte maintenance order from the date of application.  It will be betweeen 1/3rd ot 1/2 of his earnings.  But, if he is working in dollar, pound country, that courts will not convert that amount into indian currency and award 1/3rd of it,  for the reason that cost of living there also high.  But keeping your status, the courts will grant good part of that amount so that you need not to be burden on your father after he spent lavishly in marriage to get this son-in-law who hops in and out of country with a fond false hope that you and your child would be good taken care of.