TOKYO, June 18 (Reuters) - The president of Tokyo 2020 organising committee, Seiko Hashimoto, said in an interview she was considering adopting a cap of 10,000 spectators for Tokyo Olympic stadiums, the Sankei newspaper said on its web site on Thursday evening. The final decision will be made at a meeting to be held as early as June 21 among Tokyo 2020 organisers, the International Olympic Committee, International Paralympic Committee, Japanese government and Tokyo Metropolitan government, the paper said.