In an earlier post  we have featured examples of citizen media videos of national anthems sung in indigenous or less spoken languages.
National anthems are usually written in the official or the most commonly used language of the state. India's anthem Jana Gana Mana, which is 100 years old, is written in a Sanskritized version of Bengali. Both these languages are among the 22 official languages of India. Here is the Sanskrit version (with English subtitle) and here is the Bengali version . But what you will rarely stumble into is the silent  Indian national anthem in sign language:
In many countries it is prohibited by law to sing national anthems except the national language(s). Lupang Hinirang (Beloved Country) , the national anthem of the Philippines was first composed in 1898 by Julián Felipe, with lyrics in Spanish. The anthem was later translated into Tagalog. The Flag and Heraldic Code  (1998) of Philippines specifies, “the National Anthem shall always be sung in the national language within or without the country”, and provides fine and imprisonment penalties for violations.
Although according to the 1987 Philippine Constitution Filipino and English are the official languages, we can find in Internet versions of the national anthem sang in other languages of Philippines. Here  is the Philippine national anthem sang in the Eskayan  language:
The Philippine national anthem in Butuanon language :
You can find more examples in the internet.