you can use an LED strip here. that's the most common

thanks mam so incase of strip I can go for lesser gap between round portion and flat false ceiling portion

the more gap you have the more light will diffuse. the beauty of cove lights comes from that gradient. if you have a small space then that look won't come. additionally, refering to your previous post, it will also be a place for pests.
If you want this design, I would suggest you go with an LED and cover the gap with an acrylic cut out. that will give a nice effect. or create two levels, let the flat part stay where it is and make the circular one a recess

mam good idea u have LED and acrylic part i understood but recess part not understood can this circular part stick on flat part and than we can give round fixture in centre of circular part

mam pl suggest false ceiling lights type and wattage for hall 11' 10"×16' 9"

ya mam presently local level managing so problems are there

yes. which is where I provide consulting services. looking forward to connect with you