Engage a lawyer to file a reply (WS) "only" instead of fighting this case in court. Seeing the greed of lawyers for money, I can bet that any lawyer would take you the route of dowry case (498A) as Advocate Chandrasekhar hinted in one of her reply. After this case, he could loose his job and you could end-up with no maintenance. These cases reciprocate to each other. Only benefit would be given to lawyer who take advantage to these gender biased law to earn more money.
Beware from lawyers in the court!!!
You need to file WS and wait for sometime to start the mediation. Judge would start mediation after the initial hearing. In mediation, you could let him know that what you need from him in a precise manner. I see your maintenance call is totally justified and should not be deniable either by your estranged husband or by law. You can file maintenance claim (CrPc 125) any time even after divorce if you have not received any maintenance.
As your husband has filed the petition, so you can remain mum for sometime. One advantage I can see for not filling CrPc 125 now is that you would beat the hypothetical situation which your husband has built around alimony and maintenance. If everything goes smooth then reunion would not be messy and family trust would be maintained. I have seen couple of people changing their perception but stuck at the last point due to court cases.
I am not too sure what's the status of your marriage but give it a chance in mediation. Speak out without any hesitation in mediation but be watchful what you say in court.