It all depends on quantity of steroid dose and rise on sugar level different for different patients. For example few patients may have high  increase in blood sugar with very low dose steroid also..while others tolerate high doses better. Various factors like age,  how long it's been they are suffering from diabetes ,genetic predisposition,and hiw long it's been they have diagnosed with covid,'also any other comorbidities like hypertension coexist have to be cross checked.

It’s not like fixed amount of raise in blood sugar level...it needs to be manage according to patients response...need to watch on sugar level and manage it

That is one property of steroids- increase production of glucose by all means

Medical science can't give you the exact answer. Because there is never such linear relationship between steroid dose and blood sugar level. It is multi factorial and variable in person to person. It can't be predicted but it can be checked. Check blood sugar level regularly and consult doctor if high readings  noted.

Not fixed, depends on patient. Continue monitor sugar

There is no fixed amount for the rise in bsl but you need to monitor the levels .