Does weight of fork oil has anything to do with it as my interceptors both front forks have oil leak while replacing fork oil seals should i change to any specific weight of oil as my weight is 80 kg
Yes, the viscosity (weight) does matter. You are asking for a specific recommendation for a somewhat subjective question. So while there are wrong answers _ there is no universal, single right answer. But I'm willing to offer one, below.
Weight matters as a finer point of the ride quality. As a rule, the first choice is to get a quality brand oil because some times some companies just re-lable various lubricants as fork oil. Also, as you may have read, different companies use different numbering systems. That can drive you mad.
Once you have established a reliable brand that you can get on a consistent basis _ stick with that brand so that over time you can dial into exactly what works for you and the road surfaces and pace that defines
your needs.
Pick the weight in the middle of the range they offer. At 80 kg (177lb) you are in the middle. Example; if the choices of brand "X" available to you are 5, 7.5 and 10 … pick 7.5 if they offer 5, 10 and 15 … pick 10. You'll be fine.