Hi @Urmesh,
When selecting fixings, you should always start by checking the manufacturer's recommendations for their specific product. They will usually either include fixings or have recommendations for what fixings would be suitable.
Do they have any kind of recommendations in their installation instructions? If so, can you advise what they say?
If not, I could recommend something that should be suitable if you can let me know whether you are drilling into timber framing, steel framing or brick.
To put it really simply, you would just angle the screws differently so that they do not hit each other. If the screw holes are perfectly level, then have the screw on one side of the corner angle upwards slightly and the other one downwards slightly.
Let me know what you think.
Jacob
