Question

the mirror was obviously made in India: rewrite using adjective form of obviously

Answer 1

Obvious is the Adjective form of Obviously. 
Thus, we have to use the word Obvious while rewriting the sentence. 
We need a pronoun and the perfect pronoun will be 'it'. 
It will be followed by an auxiliary verb 'is'
Now we use the adjective- 'obvious'

When we say that- ' It is obvious'
A question comes to our mind that is 'what is obvious?'
Thus we use the word 'that'.
It is followed by the actual statement that the mirror was made in India.

Thus,
The sentence is- 
"It is obvious that the mirror was made in India."

Answer 2

The adjective form of obviously is obvious.

When the sentence “The mirror was obviously made in India.” is rewritten using the adjective obvious, it becomes

It is obvious that the mirror was made in India.

Both sentences have the same meaning and represent the same information.