As there is Buy/Sell Market Order. Buy/Sell Limit Order.
How to place Buy/Sell Stop Order. Please don’t confuse it with Stoploss order.
For Example Nifty is at 6500. Now I want to place a Buy Stop Order at 6510, so when price touches 6510 it automatically buys certain lots. Vice versa for Sell Stop order.
Getting your question, you need to use the same Stop loss order window to place such an order.
So, if you want to buy only at 6510 when CMP is 6500, Place a buying SL order with a trigger of 6510, so your buy will get executed only once the market goes to 6510 and above.
If you want to sell only below 6490 when market is 6500, place a selling SL order with trigger of 6490.
Check this post on SL orders.
Stop Loss order are nothing but normal Market and Limit orders with a trigger value (when to place the order).
You can use both SL-M and SL-L order for achieving this (what u mentioned in your question).
If you want to buy at 6510, use a BUY order with Stop Loss trigger at 6510 (remember, current market price should be less than 6510 otherwise it get executed immediately at market price)
In case u use a SL-L order set the limit price little above the stop loss trigger say price at 6512 and trigger price as 6510.