To answer your query, once both of the below orders get executed, you will not be holding any net position in “goldseptfut” i.e. as you correctly perceived, “both these orders will be executed on the same lot”.
NRML BUY LIMIT for goldseptfut at 2615
NRML SELL LIMIT for goldseptfut at 263
In short,
“Your net position for a particular scrip will always be the difference between the cumulative buy quantity and the cumulative sell quantity irrespective of the number of trades you have taken, provided you are using the same product code for all such trades.”
On the contrary if you use different product codes, i.e. NRML for buy order and MIS for sell order, you will see two different admin positions with Net quantities as 1 and -1 respectively (in lots).