how to proof wif's sallery?

The burden to prove spouses earnings lies on the party taking the plea. You may make a representation to the Company asking for the salary slip of their employee i.e., your wife quoting the purpose for such request. The Company may refuse to give the salary slip however, they can provide with the particulars of your wife’s earning with them.

I hope that you are aware what really counts is the real capacity to earn.

Capcity to earn is not equal to real erning. In an unsure job market, capacity to earn is not a sure enough way to really earn.

It is decided from case to case basis.

Yes if a wife's present earning is sufficient for her maintenance, IM may not be granted for her maintenance.

“Anglo Saxon jurisprudence” means ‘no person can be allowed to incapacitate himself’ relying on this well settled legal preposition the Courts have given weightage to the capacity to earn in cases where either party fails to prove the real earnings of the other party. The Courts have opined in catena of judgments that although the complainant (wife) has been working in the past but the situation today is that she is not earning and that she has no money to sustain herself but then it cannot be denied that she is in a capacity to work and with earnest effort she shall be able to search a suitable job for herself. As far as the maintenance of the complainant is concerned Courts do not incline to pass any orders for maintenance.

I am not sure though.  There are so many other factors which get into the arguments for the one who is asking for IM

The gender based discrimination in the jopb market

Income of the spouse eeking maintenance

Length of marriage

Income  and life style of her spouse

How much she is earning 

Place where she is living( urban , rural, metro) 

Change in price index/rate of inflation, etc. 

The life style which she had been used to ( not luxurious but fairly comfortable, where her basic needs such as health, nutritious food, decent clothing, transport, and such others ) .

There are judgments where the court has opined that you cannot bring a woman down to a miserable status of living and after all divorce should not become an instrument to push women into poverty.

Scenario 11: if a person is capable , and is not able to get a suitable job, would she go serve as a domestic servant or take up job of a peon?

It is from case to case basis that the judgment would differ. It is the strength of the argument and the reflection of the truth that would also matter. And this also is a settled fact.

Scenario 2 : A  woman earns, but her income pre marriage used to be supplementary income for the household for whatever reason, be it male ego or her own preoccupation with the unpaid domestic and caring work, so is that women supposed to neglect her health, residential needs in a decent locality, fairly nutritious food, medical expenses?

In the job markets CVs are looked into on a competitive basis.

Again,  suppose a woman has a low profile CV ( for whatever reason again and say earns 10,000 per month and out of which now she has to pay 7000 for rent in a metro city, would honorable judges will not see into it that for Rs 3000, she cannot even have a month's grocery for herself in the times of rising inflation. And what about her other expenses?

I am not talking about the case of the querist, but your interpretation of Anglo saxon jurisprudence which has started taking in equity aspect or is willing to take in equity aspect. It is now influenced by  treaties such as CEDAW and Beijing Platform of Action  if an advocate really can leverage on these documents, because CEDAW is the treaty which influences the policy making processes and legal interpretation heavily.

again I say if any advocate leverages them powerfully and truthfully.

There cannot be hard and fast rules in the cases of maintenance.

Sufficient to maintain-- sufficient is relative( again I am not talking about luxurious but a simple yet comfortable life which does not further decapacitate a person to actualize her full potential . The resources whether her own earning, or her own earning combined with part contribution from her spouse, or the entire contribution from her spouse( as in the case of a home maker) should be sufficient enough to live a life of dignity ( again I am not equating dignity with luxury, but even a simple and healthy life and living environs need certain amount every month for which the income of a spouse may or not be enough).If not enough, then the case has to be fought with deeper analysis and interpretations.

Apologies to the querist, as the above post may or may not be helpful to him.