How to create rails project with specific rails version?

1) how to create rails project with specific rails version

Option 1: 

$ mkdir myapp
$ cd myapp
$ echo "source 'https://rubygems.org'" > Gemfile
$ echo "gem 'rails', '5.0.0.1'" >> Gemfile
$ bundle install

$ bundle exec rails new . --force --skip-bundle

If you check the entry for rails in Gemfile, it should be like this:
gem 'rails', '~> 5.0.0', '>= 5.0.0.1'
You should update it to the exact version needed for the application:
gem 'rails', '5.0.0.1'
Now, the final step:
$ bundle update

Option 2: 
rails _4.2.7.1_ new MYAPP