[Solved]-Want to set the y axis ticks to a fixed value Highcharts-Highcharts

in graph 1, y axis looks clumsy with lot of ticks. is there a way where these ticks can be set to may be "3" on y axis. this should remain constant for any data points, ticks should always 3

use tickamount property:

yaxis: {
  tickamount: 3,
  ..
}

api reference: https://api.highcharts.com/highcharts/yaxis.tickamount

also in the graph 2, there is an extra horizontal line, below 0. is there any way i could avoid it, so that reference is always from 0 than having lines below 0.

yes, you can for example set softmax property. highcharts is unable to calculate an axis scale if there are only 0 values.

yaxis: {
  softmax: 1,
  ...
}

api reference: https://api.highcharts.com/highcharts/yaxis.softmax