I have installed nRAY, distance 1200 miters it works perfectly with fiber speeds, the only problem is that slightest rain will disconnect it. what could be the problem is there anyone out there with same problem, how did you go about it.

60 GHz is highly affected by rain. Can you split the path into two shorter paths?

You could try changing channel. Around 60000 is worst for rain (i.e. 58320), higher is better: try 64800 and above.