i have a son born in india for indian . and i was married to a german before 17 years and i have daughter for german. but i was too late to settle in germany 2011 now my daughter is 12 and my son is 22 years old. now i am not able to bring him inside the germany because he need the sponsership. we are under the government suport. no job to me as well as my husband.. can any one advice how to proceed.

no chance!

For visit visa 3 months,you can send a letter to your son and ask him to approach the nearest german embassy in inida. if you are a german citizen then there is no need to send verpflichtungserklärung document but your son has to declare some money in the account if embassy request, normally for german citizens verpflichtungserklärung is not mandatory but you son has to show the birth certificate mentioning the relation with you.

If your son apply for child reunion visa, its your indian husband has to agree, but there is lots of formalities here you may get stuck up, you have to show your income.

i hope better your son can apply for some educational courses in germany which are available with scholorship and not much expense...