Your kid is at an age where sleeping separately – in a different room other than parents, may or may not share with siblings – is the ideal way to develop independence and privacy.
What you need to know
However in an Indian family it can happen much later if the kid is a single kid and also if the other sibling is too old or too small compared to a 7-8 year old. Some kids would feel depressed or not willing to sleep separately while some others who are more outgoing and have observed the same in western culture through stories/books/TV would want to sleep separately. Normally the first reaction of your 7-8 year old would be a “No”, but it is advised this is the age, at least at the end of 7 years they should be able to sleep alone without force or fear.
What you need to do
You can set their mind towards this by making it as an interesting event of their age and letting them know in a few months that they can do so. Let them initially start with a few days in a week and then gradually every day. Decorate the kid’s room as per their liking (of course providing with suitable choices to select from) so that they feel it to be their own.
Some kids might face fears or have phobias but console them and be with them initially and let them overcome it themselves. If your child is not at all happy and feels depressed or fearful it is ok to provide a few more months but let the thought be there in them that it is good to become an independent person and be self-reliant from now on. Children who have slept with the parents until the age of 3 are more likely to have lesser stress later in their life, have better sleep patterns and better cognitive control, but in an Indian setting it is acceptable if you allow your 7-8 year old to sleep until this age if they are the only kid.