VahegurooJee I went to school in India till age 10. So can only provide information till that time.
I went to a Sikh School in Delhi. Although we had a Guroodvaraa on the school property, there was very little use of it. We were not required to go and do matha tekh to Guroo Saahib. In the morning there would be Hukamnamaa read and then Ardhaas. After that was the Jan Gan Mangal Indian National Anthem. I still don't know why we did it since the school I went to was one of the campsites during 1984 for Sikhs. We actually celebrated Nehru's day. I don't recall what the day was for but we used to get a banana and Pakorey. And then there were other Hindu holidays that we celebrated or had days off for. During Vaisakhee we did have langar though. Sorry if I am going off topic but I have to tell you how a Sikh School in Delhi used to or maybe still is working today.
We had a divinity class which was as close as we could get with learning about Guroo Saahibaan. It was a class where we learned Saakhees, and Baaniaa. Other than that the history classes mainly focused on outside world history (colonization), Indian history mainly the Independence Era, and Geography. They might have taught Sikh History later on, in senior classes but this is as far as I learned.
Another thing that still surprises me is that there was never a mention of 1984, the contribution of Sikhs in 1947, or anything like that. I along with many other students were just shown to believe that there is no better democracy in the world as India, and we are the same as Hindus (religion wise).
Personally speaking all the history I have learned relating to Sikhs and Sikhee has come to me from my family, and after coming out of that school. Other people might feel differently but this was my experience.
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥