ANSWER:

Yes, he can, by repenting and doing a lot of voluntary good deeds and worship, especially night prayers, besides completing all the obligatory acts of worship and staying away from haram and sins.

A person committed a lot of minor and major different types of bad deeds in the past. Also, most of the time of life of this person was spent in disobeying and spreading corruption. Can he/she still aim for the highest level of Jannah after repenting