Hi Raj Gowtham,
Thanks for your interest in Aspose.Slides.
I have observed the requirements shared by you and like to share that we have now new Aspose.Slides for .NET Api that has merged both PPT and PPTX namespaces in single API. Now, PresentationEX is replaced by Presentation class in new API. Please visit this documentation link for your kind reference.
Please share, if I may help you further in this regard.