Hi,
Changing the group name of the plugin won't solve the problem. It's the opposite, it will break it. So please don't do that.
If you don't see the plugin in the payment methods it means that you don't have the HikaShop common payment plugin on your website as it is the plugin that makes compatible the techjoomla plugins like CCavenue and 2checkout with HikaShop. If you don't have the common plugin, it means that either you uninstalled it, or you don't have the latest version of HikaShop where that plugin is preinstalled by default. In both cases, the solution is to simply install the latest HikaShop on your website and that should add the common plugin and then you will see the techjoomla plugins of the payment group as HikaShop payment methods.
Please understand that we sleep too and cannot answer all the time in a few hours, especially during the weekend. And please do not send your messages both by email and in the forum. It's more work for us and because of that it takes longer for us to reply to everyone.