Wife can ask alimony at time of filing ws only, not later

Hello you file your alimoney case any time you its not imporant you file when you file your case , but court not accept without your application you filed and once you file case court will accept. 

In contested matters, the court intervenes and decides the issue of alimony/maintenance on the merits of each case. The power of the court to grant alimony is not limited to cases where the decree is obtained by the wife. Courts have powers to grant alimony to the wife even where the husband is granted a decree. It is quite possible there may be no alimony/maintenance awarded at all depending upon the facts and circumstances of the case. Assessment of the amount of permanent alimony is entirely the court's discretion.

Permanent Alimony under S25 that may be in installments or lumpsum whatever it may be, you can be apply even after the Decree of Divorce.

If yo are also interested in Divorce, then better start negotiations for mutual divorce by asking the court to refer your case to lok adalat or court reconciliation or any external counselling center, if it fails then only proceed further in the ongoing case.