PROVIDENCE, R.I. — Competing demands on the proposed state budget — such as car tax cuts, free tuition and development incentives — could be tougher to satisfy this year with state revenues sagging heading into the last four months of the fiscal year.Unlike the previous six years when tax collections exceeded estimates at this point in the year, as of February, revenues were $27.3 million, or 1.3 percent, behind the estimates developed in November and used by Gov.