You have to file a petition for custody of child before the family court along with an application of interim custody for welfare of child as child is of age below 5 years.

1) file police complaint against husband if he is refusing to permit you access  to your child 

2) file DV case seek sole custody of your child, maintenance, right to stay in your matrimonial house 

Upto 5 years of age of your child you can take custody easily.

After that welfare of the child shall be the main criteria for deciding the custody of child. Better financial condition alone is not considered favourable conditions for a child's welfare. Other mental and emotional supports required for well being of child is also considered together with all other factors.

First of all you did great mistake by leaving the child while getting separated from your husband.

You have made a Himalayan blunder which is unlikely to be corrected anymore.

To get back his custody you have the option of filing a suit for custody under Guardian and Wards Act but therein you are unlikely to get anything more than visitation of the child unless the child after gaining his adequate intelligence unequivocally desires to get reunited with you before the Judge when the Judge wishes to know his wish.

Good luck.

You can apply for child custody and as a mother court may grant you the custody. As mother is best natural caretaker. And he is less than 5 years.

A case must be filed for divorce and a case must be filed in the court of wards for the child's custody. 

If you are in a better position than him the court shall grant you custody.

Regards 

You can file custody and contest it. He can't only accuse you of extra marital affair. He needs to prove the same in court

At this point of time you need to go to the police and file FIR against your husband also you need to mention that your two years son is with him and you need to get him as he needs care of mother.

The Guardian and ward act also support custody of child below 5 years with mother.

legally mother is entitled to take care of baby and she is the first guardian. You will have the custody of your baby as he is only two years and only mother can take care of child at this tender age and if any case is filed for custody you have to prove that you are the best care taker of your child with all amenities for his future.

Hi

Immediately file Petition in the court for custody of child, giving the details of probable setbacks of your husband in taking care of the child i.e., age and ailments of his mother, other problems in taking care of child.

Further, file an interim application for visitation rights.

Good Luck

Dear Madam,

As per law if the child's age is less than 5 years, the mother can claim for physical custody and father can have a visitation rights. But after the child has crossed the age of 5 years, the physical custody and up bring of the child will be considered by the court. So, if the child is in your husband’s custody then you can file a case under Guardian and Wards Act seeking custody of the child if your husband denies you for the same.

In custody matters, paramount importance is child welfare.

In the case of a boy or an unmarried girl—the father is natural guardian provided that the custody of a minor who has not completed the age of five years shall ordinarily be with the mother. 

File custody application in court.

You may have to file a child custody case seeking custody of your child and also interim custody since the child can be in the custody of the mother till it attains 5 years of age.

In order to put more pressure on him you may file DV case and other criminal complaints with the police.