Nearly 31,000 California Lottery winners will begin receiving tax withholding statements next week for their 1986 winnings totaling more than $202 million, officials said. As required by law, state officials have notified the Internal Revenue Service of those lottery winners of $600 or more during the 1986 tax year. Larry Herrback, lottery manager of fiscal systems, said individual winners will receive forms showing prize amounts which have been reported to the IRS. In addition to the $600 threshold for reporting to the IRS, the California Lottery is required to withhold 20% for federal income tax for all prize winnings over $5,000. Lottery prize winnings are exempt from the California state income tax. Taxpayers are permitted to claim the amount of lottery losses only up to the amount of winnings as a tax deduction.