// replace original input from
<input value={this.state.numeralVal} className="" placeholder="" onChange={this.onChange} />
 
// like this
<NumeralInput value={this.state.numeralVal} className="" placeholder="" onChange={this.onChange} />

let NumeralInput = require('react-numeral-input');
 
module.exports = React.createClass({
  getInitialState() {
    return {
      numeralVal: 1000000
    }
  },
  onChange(val){
    this.setState( {numeralVal:val});
  },
  render() {
    return (
      <NumeralInput
        value={this.state.numeralVal}
        className="form-control"
        placeholder=""
        onChange={this.onChange} />
    )
  }
});

<NumeralInput value={this.state.numeralVal} className="" placeholder="" onChange={this.onChange} minLength={2} maxLength={10}/>