Generate a HTML grid layout.
6 rows, 3 columns
Here is a simple HTML code that will generate a 6x3 grid layout:

```html
<!DOCTYPE html>
<html>
<head>
<style>
.grid-container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-gap: 10px;
}

.grid-item {
  border: 1px solid black;
  text-align: center;
  padding: 20px;
}

</style>
</head>
<body>

<h2>6x3 Grid Layout</h2>

<div class="grid-container">
  <div class="grid-item">1</div>
  <div class="grid-item">2</div>
  <div class="grid-item">3</div>
  <div class="grid-item">4</div>
  <div class="grid-item">5</div>
  <div class="grid-item">6</div>
  <div class="grid-item">7</div>
  <div class="grid-item">8</div>
  <div class="grid-item">9</div>
  <div class="grid-item">10</div>
  <div class="grid-item">11</div>
  <div class="grid-item">12</div>
  <div class="grid-item">13</div>
  <div class="grid-item">14</div>
  <div class="grid-item">15</div>
  <div class="grid-item">16</div>
  <div class="grid-item">17</div>
  <div class="grid-item">18</div>
</div>

</body>
</html>
```

This code will create a grid with 6 rows and 3 columns. Each cell in the grid is represented by a `<div>` element with the class "grid-item". The grid is created using the CSS grid layout, with the "grid-template-columns" property set to "1fr 1fr 1fr" to create 3 equal columns. The "grid-gap" property adds space between each cell in the grid. Each cell is styled with a border, centered text, and padding for readability. You can modify the content and styling of each cell to fit your needs.
Complete the following task based on the instruction and optional input provided.### Instruction:
Generate a HTML grid layout.

### Input:
6 rows, 3 columns

### Output:
Here is a simple HTML code that will generate a 6x3 grid layout:

```html
<!DOCTYPE html>
<html>
<head>
<style>
.grid-container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-gap: 10px;
}

.grid-item {
  border: 1px solid black;
  text-align: center;
  padding: 20px;
}

</style>
</head>
<body>

<h2>6x3 Grid Layout</h2>

<div class="grid-container">
  <div class="grid-item">1</div>
  <div class="grid-item">2</div>
  <div class="grid-item">3</div>
  <div class="grid-item">4</div>
  <div class="grid-item">5</div>
  <div class="grid-item">6</div>
  <div class="grid-item">7</div>
  <div class="grid-item">8</div>
  <div class="grid-item">9</div>
  <div class="grid-item">10</div>
  <div class="grid-item">11</div>
  <div class="grid-item">12</div>
  <div class="grid-item">13</div>
  <div class="grid-item">14</div>
  <div class="grid-item">15</div>
  <div class="grid-item">16</div>
  <div class="grid-item">17</div>
  <div class="grid-item">18</div>
</div>

</body>
</html>
```

This code will create a grid with 6 rows and 3 columns. Each cell in the grid is represented by a `<div>` element with the class "grid-item". The grid is created using the CSS grid layout, with the "grid-template-columns" property set to "1fr 1fr 1fr" to create 3 equal columns. The "grid-gap" property adds space between each cell in the grid. Each cell is styled with a border, centered text, and padding for readability. You can modify the content and styling of each cell to fit your needs.