If the stock fails to comply with the regulations of the exchanges, then it can get suspended. When such a situation arises, the stock can’t be traded on the exchange and you won’t be able to see them on the Neo app. 

There is a list of suspended stocks on both BSE and NSE’s website. 

The suspension of the shares will have an influence on its value, however, it does not exactly mean that the value of the stock will turn zero. It only results in ban on trading in an exchange. Suspension on the shares can be revoked if the company manages to comply to all the regulations of the exchanges. In a bleaker scenario, if the company gets suspended and shuts down, you will have to accept the losses.