Nepal has thrown open the doors to foreign tourists after keeping them out for nine months as the country battled the Covid-19 pandemic. All tourist visas have been restored, and foreign visitors are now free to fly into the country, the Department of Immigration said, but the land borders are still closed.
In some places in himachal there are restrictions like lahaul and spiti but most of the places in himachal are open like manali , kullu, dharamshala , Mcleodganj, Kasol etc. So you can visit these places easily.
I have few friends who recently visited Mathura. They didn't face any problem. Just that while coming back, Noida's border was close if you are entering from Mayur Vihar side. They had to take a small detour.