Please correct the mistakes if it has any.

[Muhammad Raza Wynne]

Major Petkoff, who is far from being a soldier, retorts well to the suggestion, which is made by Cathrine regarding the promotion of Sergius, that he must be promoted.

 

[J&K Tutoring]

This sentence is very confusing! Possibly context would clear up some of that.

1. Major Petkoff is "far from being a soldier"? How can someone achieve a relatively high military rank and not be a soldier?

2. "Retorts well..." sounds strange to me. Look at other examples of the use of retort.

3. Remember that, in any language, most of the things we talk about happened in the past. In English, our verbs will change to reflect a time frame.
3a. "Major Petkoff is..." This is a general statement that always applies, so present tense is appropriate.
3b. "retorts to the suggestion..." This passage relates something that happened in the past, so it should probably be in past tense.
3c. "...which is made by Catherine..." Same as 3b- a past event, so past tense.
3d. "...he must be promoted." We don't have context to know who is/was/may be promoted and whether that promotion has taken place at the time of writing, so hard to suggest the best verb form.

I would like to suggest an alternative, but I don't feel confident guessing the meaning of your example sentence.

 

[Muhammad Raza Wynne]

Thanks, your comment helps a lot. Could you please tell me that why "he retorts" is not apt or why is it strange to you? Doesn't it mean "he answers"?

 

[Muhammad Raza Wynne]

My teacher advised me that whenever you do criticism use present tense. That's why I wrote the above paragraph in present tense.