Which algorithm to find the evolutionary relation of 5 sequences?
If you work with protein coding sequence and on the DNA level their to divergent, then it is better to use the amino acid sequence for alignment and phylogenetic reconstruction.

Better sampling can also help you, for this you can check the online databases with BLAST to find similar sequences that would fill the gap.

The problem with sequences with low sequence similarity is that it is difficult to identify homologous positions/characters and all alignment based methods rely on the assumption that the aligned positions are homologous.

Finally, there are alignment-free algorithms as well. (https://en.wikipedia.org/wiki/Alignment-free_sequence_analysis)

In general about algorithms for phylogenetics:

Nowadays, journals usually require you to run maximum likelihood (ML) analysis or Bayesian analysis. Both of these methods are referred to as model based. The most common programs used for these are RAxML (ML) and MrBayes (Bayesian). Another common software is MEGA (Molecular Evolutionary Genetics Analysis), which can run different tree building algorithms.

Usually, for quick reference maximum parsimony or neighbour-joining trees are good. For publication a maximum likelihood tree is very useful, since it returns a single best tree. While Bayesian analysis and maximum parsimony return a collection of trees.

It is also helpful different algorithms and if all return similar trees than you can be more sure about the relationships.