Yesterday at 1 pm my father started problem with speach we meet dr he asked for mri and we found blood clot in brain and treatment started at 7 pm. now in how many days clot dissolves ? today morning their is improvement in speech what is risk now ?

Without knowing what type of intracranial blood clot it is --epidural,subdural,intracerebral ,or within an artery it's not possible to give a prognosis. However return of speech is a favorable development. The neurologist and/or neurosurgeon involved in his care are best qualified to give you any up to date information about diagnosis and prognosis.

Sounds like your Father had a stroke and has been treated very appropriately. The improvement in his speech is encouraging. There could be future risks if longterm treatment is not employed. Your doctor knows the case best and can discuss prognosis and plans to maintain good health.