The RWA cannot construct a temple in the society without permission from the municipal / corporation, and if RWA does not have permission then there cannot be construction. The RWA needs permission from the concerned authorities. You need to inform the concerned authority which is the municipal corporation about such unauthorised construction by the RWA.
You have to send the society RWA a legal notice with the help of your advocate and if they do not respond then you can file a civil case against them in a Court and praying for injunction to stop the construction of the temple in your society. They can’t violate as the original sanction plan as per the original sanction plan the construction of the temple needs to be done.
You also have to pray for interim injunction during the pendency of the suit under Order 39 of the Civil Procedure Code, 1908 or a mandatory injunction under Section 38 of the Specific Relief Act, 1963 in your application. You can also file a writ petition and get a stay in your favour from High Court. You can approach to the Ghaziabad civil court against the construction and can get an injunction order against the society.