Read this judgment from Supreme Court of India which is important in more than one ways.

Lower Courts are impleaded as respondents:

It is not proper or even justified on the part of the appellant to implead the courts as respondents and respondents 1 and 2 are, therefore, struck off from the record of this appeal.

It does appear to us from the affidavit of the husband that it conceals more than what it tells of his income and other assets. Attempt has been made to conceal his true income and that leads us to draw an adverse inference against the husband about his income that it is much more than what is being disclosed to us.

Considering the diverse claims made by the parties one inflating the income and the other suppressing an element of conjecture and  guess work does enter for arriving at the income of the husband. It cannot be done by any mathematical precision.

Court has to consider the status of the parties, their respective needs, capacity of the husband to pay having regard to his reasonable expenses for his own maintenance and those; he is obliged under the law and statutory but involuntary payments or deductions. Amount of maintenance fixed for the wife should be such as she can live in reasonable comfort considering her status and the mode of life she was used to when she lived with her husband and also that she does not feel handicapped in the prosecution of her case. At the same time, the amount so fixed cannot be excessive or extortionate.

Date from which Interim maintenance can be claimed:

If wife has no source of income it is the obligation of the husband to maintain her and also children of the marriage on the basis of the provision contained in the Hindu Adoption and Maintenance Act, 1956.
Her right to claim maintenance fructifies on the date of the filing of the petition for divorce under the Act.

The court has discretion in the matter as to from which date maintenance under Section 24 of the Act should be granted.