Mars in the 11th house of horoscope is an intriguing combination. On one hand, being a malefic planet placed in most favorable upachaya house, it gives good results, but on the other hand, it might create some grave situations for the native if it's not dignified and has some malefic associations and lacks aspects from benefics.
Mars in the eleventh house casts its aspect on the second, fifth and sixth houses. By its aspect on the second house, it makes native argumentative. If it's debilitated, i. e. in Cancer, it may make a native speak very foul things and argue unnecessarily. If it's exalted, then its aspect will make a native an excellent debater, and aspect of Jupiter or aspect of lord of second house, either to Mars or to the second house will make native a linguist. Second house represents language and speech apart from many other things and aupicious aspects on it or association of Jupiter in various combinations with lord of second house make a native a refined linguist and even a polyglot.
Mars' aspect on the fifth house makes one a logician and a romantic person, especially if it's exalted it gives very sharp intelligence. Debilitated Mars however is more likely to cause psychosis unless some favorable aspects are present for the cancellation of it. Aspect on the sixth house makes one capable of doing well in service and it might cause bulky body which brings in diseases, especially if Mars is not in its own or exaltation signs and has only inauspicious aspects.
Mars in the 11th house increases wealth and material possesions but since Mars is in the 8th from the 4th, it might cause concerns on account of his mother's health if neither of Moon or the lord of the 4th house are favorably disposed.