The meaning is the following

The writing is imperfect but this doe not mean it is any good. The story is that the main character faces many obstacles and the fact that we see him to overcome them , distract us from seeing that what he went through is unevenness or unfair

The other two options are completely out of scope

Ask if still unclear

ANSWER CHOICES - overriding, unevenness, exquisite

The short passage sets up a series of contrasts and creates the logic of “genius overriding (Blank 1) great obstacles" as overriding means to take priority over. The contrasts continue with the work being “so extraordinary that we forget to be surprised at its unevenness (Blank 2)" and with the verse being sometimes exquisite (Blank 3) while “at other times the rules of our prosody are absolutely ignored.”

The Sheaf Gleaned in French Fields is certainly the most imperfect of Toru Dutt’s writings, but it is not the least interesting. It is a wonderful mixture of strength and weakness, of genius (i) __________ great obstacles and of talent succumbing to ignorance and inexperience. That it should have been performed at all is so extraordinary that we forget to be surprised at its (ii) __________. The English verse is sometimes (iii) __________; at other times the rules of our prosody are absolutely ignored, and it is obvious that the Hindu poetess was chanting to herself a music that is discord in an English ear.

First Blank

The following sentence fragment displays parallelism:

It is a wonderful mixture of strength and weakness, of genius (i) __________ great obstacles and of talent succumbing to ignorance and inexperience.

Thus, I would be looking for a display of strength when filling the first blank. Only overriding gives me what I need.

I would now go over to the Third Blank.

The English verse is sometimes (iii) __________; at other times the rules of our prosody are absolutely ignored, and it is obvious that the Hindu poetess was chanting to herself a music that is discord in an English ear.

The phrase "at other times" implies a contrast between the two parts of the sentence. Since the second part talks about rules of prosody being absolutely ignored leading to a music that is discord in an English ear, I need a word that gives me an exact opposite description of the verse. The word is exquisite.

Now we are in a position to attack the Second Blank.

That it should have been performed at all is so extraordinary that we forget to be surprised at its (ii) __________.

The word for the blank is actually given by the sentence that follows it, which describes the verse as being simultaneously exquisite and possessing unruly prosody; apart from sounding discordant to an English ear. Therefore, unevenness is the best fit.