After vetoing a Republican budget proposal this afternoon that contains deep cuts in Medicare and Medicaid, President Clinton said he would present his own plan to balance the budget in seven years. Clinton agreed revise his initial goal of balancing the budget in seven to 10 years to a seven-year timetable as a condition of resolving the temporary-spending deadlock that caused a partial government shutdown last month. The Clinton plan calls for smaller tax cuts than the GOP version, and will also ask for smaller spending increases on domestic programs than his previous budget includes. On Medicaid and Medicare, Clinton has not changed his plans. His budget seeks cuts of $124 billion from Medicare and $54 billion from Medicaid, far less than the GOP-requested cuts of $433 billion.