The Board of Selectmen at its meeting Tuesday will hold its annual tax classification hearing. In it, the board will decide whether to maintain Tewksbury’s existing policy of having a split tax rate, and if so how much of the residential tax burden to shift to businesses. The decision will be subject to approval by the state Department of Revenue. Also at Tuesday’s meeting, selectmen are set to receive an update from the town’s legislative delegation on the state’s financial situation. The delegation consists of state Senator Barry R. Finegold, an Andover Democrat, and state representatives James R. Miceli, a Wilmington Democrat, and Paul Adams, an Andover Republican.