Please provide detailed information on the Indigenous People's Rights Act (IPRA), enacted by the Congress in 1997, and on the progress made, and difficulties encountered, by the National Commission on Indigenous Peoples in the implementation of the Act.
10. 请提供详尽资料，介绍1997年国会颁布的《土著人权利法》，并说明土著人民全国委员会在执行该法案时取得的进展和遇到的困难。