Tampering of contents by the respondent's advocate

One cannot file a WS and give a copy which has different details. It will amount to fraud. You will file reply based on the details given in the copy, which finally wont match with the original WS/petition. In other words, it will come out sooner or later and her WS/petition wont stand. Apply for a certified copy of her petition, then your problem is solved. You can also go ask the record section either through your lawyer or in person asking em orally to show the original petition. It also appears that your lawyer is unnecessarily getting you worried. It may also be that, he is compromised. This case will go on for years. Its best that you change your lawyer. The lawyers duty is to find solutions for your legal problems, not to get your worried, am sure there is something fishy.

Just approach the Court's office where they give certified copies of court filings. Ask them to give you a certified copy of the petition that you are doubting.  There is a small fee for this. If you get the copy before the next hearing, well, you have your answer. If you do not receive copy from the Court before the next hearing,  then in the next hearing, file an application with the Court  asking for an adjournment for filing a response. Cook some excuse. If you say that you are suspecting that the copy is not the same, it may not be appropriate until you confirm the same.  If later you find that the copy given to you is different, then really there is not much you can do because the other party will claim that they had given you the true copy and that you are making false allegations. In the future, before signing that you have received the copy, do a basic check to compare the two documents: The original and the one given to you. That will put the other party on notice and dissuade them from such malpractices. 

Apply and get copies yourself. Do not ask advocates to do so. This way you will control the process yourself.  

Thank you helping hand and Samir for your very valuable guidance.

I will try to get a certified copy to clear this doubt.

I will try to use services of another advocate or go in person to collect the certified copy.