Hey Rahul, Have read about people visiting in end of the march ... first week is a risk to take ... as if the previous night there is a snow or heavy rains ... you will not get the permission to go to lake ... Better change your travel dates if possible... Happy and safe Travelling!!
Hey Rahul, It depends on the weather is that day. When you will reach Cafe 15000, then the army will tell you whether you can go or not. I visited there in April ist week 2018 and I was lucky that I visited Gurudongmar lake ( path that starts after Cafe 15000 up to lake looks as it is going to heaven ). Happy travelling!!!!!