As technical analysis depends on indicators to predict the movement of a stock , why a particular indicator fails. a) after  some time of use in the market b) for particular stocks ?

Technical analysis based on the data points of a stock's price movement with time and volume. Hence the indicator you are using, it's giving the future prediction price based on the previous history of the market. Indicators are tools, so you need to understand the price action of stock with multiple time frames before you insert any indicator. I hope you can find every time the result will vary hence your future price too. You will get a better identification of price momentum.

Indicators depend on price and volume, and momentum. When a trend is intact, indicators behave accordingly and provide good signals. But when the price moves too fast, either way up or down and reverses too quickly, indicators take their time to respond. That's it. Indicators don't fail; they just take time to adjust to fast reversing or fast-moving prices.

Technical Indicators are not a tool used to buy and sell.
It acts as an additional confirmation for your method or strategy.
Note it's an additional confirmation.
The BEST indicator to use is PRICE.
Price is the best indicator, and then the Volume.
Before any indicator, price gives confirmation.
OPTION CHAIN will also give you an indication, better than any indicators.
Never Rely on Indicators.
If it were so easy to make money in the Stock Market, then 90 % + people wouldn't have lost money. ☺

The indicators are all lagging indicators. They give indication based on what price charts show. Technical analysis is never about catching the exact bottoms and top of a trend. Its about focussing on the entry and exit positions. So it can hapen at times that your indicators show buy but prices reverse. At that time, you have to use your stoploss which is again an essential thing taught in technical analysis. Even the best strategies and indicators dont’t have a 100% success rate. Prudency is in making use of that 70% or 80% hit rate as efficiently as possible. As a side note, technical indicators work relatively better in liquid stocks. So if you apply the technical studies on illiquid securities, they'll fail more often.

Depending on the major changes in the fundamentals of a company, the stock will move accordingly irrespective of technical data. I would always advise you to look at multiple factors and hedge your intraday or positional trades rather than taking one side views. In this way, even if your view goes wrong, your loss will be limited.