So far, Huawei is only being investigated for tax fraud. That doesn't mean they actually committed tax fraud. India has a huge problem with tax dodgers in general, most of whom are Indian, so they may as well investigate the Chinese as well, why not.
Excluding Huawei from the 5G rollout does seem discriminatory to me.
Your idea of reciprocal business practices seems like a recipe for war. It seems fair and everything, but only if you ignore that not all macro-economies are equal. The West already doesn't allow investment in China, which is quite alright with China. Now imagine Jack Ma being forced to buy Amazon because if reciprocity.