Is it right to lose 5-6 kg in a month?

This totally depends on where the person is starting from. The recommended average rate of fat loss is 1lb./week. A more specific guideline would be 1-1.5% of bodyweight per week. So if you are 105 kilos, 1% would be 1.1 kgs per week or 4.5 kgs per month. This is only if you want to lose fat while preserving your lean body mass. If you try to lose any faster, there is a chance you will lose some lean tissue and have some deficiencies in the long run. 

Can someone provide info on how we can factor alcohol into our diet.

Drinking on a diet is not something which is  usually recommend. However if you do feel like having a drink or so once in a while then factor it in your macros.
Make sure not more than 15% of your overall calories are coming from alcohol. You can either track it as a Carb/Fat or a combination of both.