Trending @Capgemini; Will there be any problem if I come to office for 8 days instead of 12 days for just one month.

I am currently on bench and I am supposed to come to office for 12 days in a month. I've diagnosed with a severe health issue and I will be able to complete only 8 days in this month as I will have to leave to home the next day. I will be able to complete 12 days from next month as my sister is going to come and stay with me . Do I need to take permission and to whom should I inform this so that I don't get into any problem?